Vaccines

The Food and Drug Administration has expanded an emergency use authorization (EUA), allowing the Pfizer-BioNTech COVID-19 booster shot for children ages 5 to 11 who are at least 5 months out from their first vaccine series.

According to the most recent data from the Centers for Disease Control and Prevention, 28.6% of children in this age group have received both initial doses of Pfizer’s COVID-19 vaccine, and 35.3% have received their first dose.

Pfizer’s vaccine trial involving 4,500 children showed few side effects among children younger than 12 who received a booster, or third dose, according to a company statement.

Pfizer asked the FDA for an amended authorization in April, after submitting data showing that a third dose in children between 5 and 11 raised antibodies targeting the Omicron variant by 36 times.

“While it has largely been the case that COVID-19 tends to be less severe in children than adults, the omicron wave has seen more kids getting sick with the disease and being hospitalized, and children may also experience longer-term effects, even following initially mild disease,” FDA Commissioner Robert M. Califf, MD, said in a news release.

A study done by the New York State Department of Health showed the effectiveness of Pfizer’s two-dose vaccine series fell from 68% to 12% 4-5 months after the second dose was given to children 5 to 11 during the Omicron surge. A CDC study published in March also showed that the Pfizer shot reduced the risk of Omicron by 31% in children 5 to 11, a significantly lower rate than for kids 12 to 15, who had a 59% risk reduction after receiving two doses.

To some experts, this data suggest an even greater need for children under 12 to be eligible for a third dose.

“Since authorizing the vaccine for children down to 5 years of age in October 2021, emerging data suggest that vaccine effectiveness against COVID-19 wanes after the second dose of the vaccine in all authorized populations,” says Peter Marks, MD, PhD, the director of the FDA’s Center for Biologics Evaluation and Research.

The CDC still needs to sign off on the shots before they can be allowed. The agency’s Advisory Committee on Immunization Practices is set to meet on May 19 to discuss boosters in this age group.

FDA advisory panels plan to meet next month to discuss allowing Pfizer’s and Moderna’s COVID-19 vaccines for children under 6 years old.

A version of this article first appeared on WebMD.com.

The Food and Drug Administration has expanded an emergency use authorization (EUA), allowing the Pfizer-BioNTech COVID-19 booster shot for children ages 5 to 11 who are at least 5 months out from their first vaccine series.

According to the most recent data from the Centers for Disease Control and Prevention, 28.6% of children in this age group have received both initial doses of Pfizer’s COVID-19 vaccine, and 35.3% have received their first dose.

Pfizer’s vaccine trial involving 4,500 children showed few side effects among children younger than 12 who received a booster, or third dose, according to a company statement.

Pfizer asked the FDA for an amended authorization in April, after submitting data showing that a third dose in children between 5 and 11 raised antibodies targeting the Omicron variant by 36 times.

“While it has largely been the case that COVID-19 tends to be less severe in children than adults, the omicron wave has seen more kids getting sick with the disease and being hospitalized, and children may also experience longer-term effects, even following initially mild disease,” FDA Commissioner Robert M. Califf, MD, said in a news release.

A study done by the New York State Department of Health showed the effectiveness of Pfizer’s two-dose vaccine series fell from 68% to 12% 4-5 months after the second dose was given to children 5 to 11 during the Omicron surge. A CDC study published in March also showed that the Pfizer shot reduced the risk of Omicron by 31% in children 5 to 11, a significantly lower rate than for kids 12 to 15, who had a 59% risk reduction after receiving two doses.

To some experts, this data suggest an even greater need for children under 12 to be eligible for a third dose.

“Since authorizing the vaccine for children down to 5 years of age in October 2021, emerging data suggest that vaccine effectiveness against COVID-19 wanes after the second dose of the vaccine in all authorized populations,” says Peter Marks, MD, PhD, the director of the FDA’s Center for Biologics Evaluation and Research.

The CDC still needs to sign off on the shots before they can be allowed. The agency’s Advisory Committee on Immunization Practices is set to meet on May 19 to discuss boosters in this age group.

FDA advisory panels plan to meet next month to discuss allowing Pfizer’s and Moderna’s COVID-19 vaccines for children under 6 years old.

A version of this article first appeared on WebMD.com.

The Food and Drug Administration has expanded an emergency use authorization (EUA), allowing the Pfizer-BioNTech COVID-19 booster shot for children ages 5 to 11 who are at least 5 months out from their first vaccine series.

According to the most recent data from the Centers for Disease Control and Prevention, 28.6% of children in this age group have received both initial doses of Pfizer’s COVID-19 vaccine, and 35.3% have received their first dose.

Pfizer’s vaccine trial involving 4,500 children showed few side effects among children younger than 12 who received a booster, or third dose, according to a company statement.

Pfizer asked the FDA for an amended authorization in April, after submitting data showing that a third dose in children between 5 and 11 raised antibodies targeting the Omicron variant by 36 times.

“While it has largely been the case that COVID-19 tends to be less severe in children than adults, the omicron wave has seen more kids getting sick with the disease and being hospitalized, and children may also experience longer-term effects, even following initially mild disease,” FDA Commissioner Robert M. Califf, MD, said in a news release.

A study done by the New York State Department of Health showed the effectiveness of Pfizer’s two-dose vaccine series fell from 68% to 12% 4-5 months after the second dose was given to children 5 to 11 during the Omicron surge. A CDC study published in March also showed that the Pfizer shot reduced the risk of Omicron by 31% in children 5 to 11, a significantly lower rate than for kids 12 to 15, who had a 59% risk reduction after receiving two doses.

To some experts, this data suggest an even greater need for children under 12 to be eligible for a third dose.

“Since authorizing the vaccine for children down to 5 years of age in October 2021, emerging data suggest that vaccine effectiveness against COVID-19 wanes after the second dose of the vaccine in all authorized populations,” says Peter Marks, MD, PhD, the director of the FDA’s Center for Biologics Evaluation and Research.

The CDC still needs to sign off on the shots before they can be allowed. The agency’s Advisory Committee on Immunization Practices is set to meet on May 19 to discuss boosters in this age group.

FDA advisory panels plan to meet next month to discuss allowing Pfizer’s and Moderna’s COVID-19 vaccines for children under 6 years old.

A version of this article first appeared on WebMD.com.

Twelve years after the human papillomavirus (HPV) vaccination program was introduced in the United States, the overall prevalence of cancer-causing HPV strains covered by the vaccine dropped by 85% among females – 90% among vaccinated females and 74% among unvaccinated females – a strong sign of herd immunity, a new analysis of a nationally representative database is showing.

“HPV vaccination is working well,” Hannah Rosenblum, MD, Centers for Disease Control and Prevention, Atlanta, told this news organization in an email.

“Twelve years after introduction of HPV vaccination in the United States, national data demonstrate increasing impact among females and strong herd effects among unvaccinated females,” she added. “[Although] vaccination coverage and completion of the recommended dose in the United States is lower than coverage with other adolescent vaccinations, HPV vaccination is the best way to prevent HPV infections that can lead to several cancers in both females and males.”

The study was published online in Annals of Internal Medicine.
 

NHANES survey

The authors used data from the National Health and Nutrition Examination Survey (NHANES) to examine the four HPV types in the quadrivalent vaccine before 2003 and 2006 (the pre-vaccine era) and then again between 2007-2010, 2011-2014, and 2015-2018 (the vaccine era). For females, they analyzed demographic and HPV prevalence data across each 4-year era.

“Analyses were limited to sexually experienced participants, to ensure that all those included had an opportunity for HPV exposure, and to participants aged 14-24 years with adequate self-collected cervicovaginal specimens,” the authors explain.

This resulted in a sample size of 3,197 females. Demographic and HPV prevalence data were also collected from males but only during the 2013-2016 era, because those are the only years for which male HPV typing data are available in NHANES. Again, analyses were limited to sexually experienced males aged 14-24 years with adequate self-collected penile specimens, which resulted in a sample size of 661 males.

Over the 12 years of follow-up for females, there was a steady increase in females reporting having received at least one dose of the HPV vaccine – from slightly over 25% during 2007-12 to 59% during 2015-2018. The percentage of males who reported having at least one HPV dose also increased, from 29.5% in 2016 to 34.5% in 2018.

During the earliest vaccine era (2007-2010), the prevalence of the four HPV strains covered by the vaccine was 7.3% among vaccinated females, compared with 20.4% among unvaccinated females. “By 2015 to 2018, the prevalence was 2.8% (prevalence ratio, 0.16; 95% confidence interval, 0.07-0.39). The prevalence of the four vaccine-covered types was only 1.9% in vaccinated females, compared with 4.8% in unvaccinated females (PR, 0.40; 95% CI, 0.11-1.41).

In contrast, the prevalence of HPV types that were not covered by the vaccine showed little change – from 51.1% in the pre-vaccine era to 47.6% during 2015-2018 (PR, 0.93; 95% CI, 0.80-1.08). The authors considered this a good sign because it indicates that vaccine-type HPV infections are not being replaced with other oncogenic HPV infections. Between 2013 and 2016, the difference in the prevalence of the four HPV vaccine types was smaller at 1.8% among vaccinated males and 3.5% among unvaccinated males (PR, 0.49; 95% CI, 0.11-2.20).

Again, the prevalence of non-HPV vaccine types was not significantly different between vaccinated and unvaccinated males: 30.7% versus 34.3%.

During the vaccine era, effectiveness for females ranged from 60% to 84%. For males, vaccine effectiveness could only be evaluated for the single 4-year period from 2013 to 2016, and it was estimated at 51%. Dr. Rosenblum noted that vaccine efficacy estimates were lower on this national survey than the almost 100% efficacy rates observed in clinical trials in both males and females.

“This might be due in part to many participants receiving the vaccine at an older age than is recommended when they could have been infected [with HPV] at the time of vaccination,” Dr. Rosenblum said. She also noted that because males were incorporated into the HPV vaccination program years after females, they likely also experienced strong herd effects from the vaccine, making it challenging to estimate vaccine effectiveness.

Dr. Rosenblum also noted that there have already been documented declines in cervical precancers and high-grade vulvar and vaginal precancers, as well as genital warts and juvenile-onset recurrent respiratory papillomatosis. At the same time, the incidence of cervical precancers has recently declined among U.S. females in their late teens and early 20s – “likely reflecting the impact of vaccination,” she said.

“This study is good news for the United States HPV vaccination program, and all efforts are needed to ensure that children and adolescents receive routinely recommended vaccinations [including vaccination against HPV],” Dr. Rosenblum added.
 

Editorial comment

Commenting on the findings, Rebecca Perkins, MD, Boston University School of Medicine, and colleagues point out that the COVID-19 pandemic has led to disruptions in HPV vaccination programs and has reversed much of the progress made in recent years. “During the pandemic, providers and health systems have deprioritized adolescent vaccination and particularly HPV vaccination, which in turn has led to more severe drops for HPV vaccination than for other adolescent vaccinations, and for adolescent vaccination, compared with early childhood and adult vaccinations,” Dr. Perkins and colleagues write in an accompanying editorial.

Thus, the need to compensate for the cumulative deficit of missed vaccinations over the past 2 years has created a “serious and urgent threat” to cancer prevention efforts – “a shortfall from which it may take a decade to recover,” the editorialists predict. To try and reverse this trend, several practices have been shown to improve HPV vaccination rates.

The first is a strong provider recommendation such as, “Your child is due for an HPV vaccine today.” The second is to give standing orders to allow nurses and medical assistants to administer vaccinations without requiring intervention by a physician. Lastly, programs to remind patients when vaccines are due and to recall them for appointments also work well.

“Using evidence-based methods and redoubling our efforts to prioritize HPV vaccination will be crucial to ensuring that we do not lose a generation to preventable HPV-associated cancer,” write Dr. Perkins and colleagues.

The study authors and editorialists have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Twelve years after the human papillomavirus (HPV) vaccination program was introduced in the United States, the overall prevalence of cancer-causing HPV strains covered by the vaccine dropped by 85% among females – 90% among vaccinated females and 74% among unvaccinated females – a strong sign of herd immunity, a new analysis of a nationally representative database is showing.

“HPV vaccination is working well,” Hannah Rosenblum, MD, Centers for Disease Control and Prevention, Atlanta, told this news organization in an email.

“Twelve years after introduction of HPV vaccination in the United States, national data demonstrate increasing impact among females and strong herd effects among unvaccinated females,” she added. “[Although] vaccination coverage and completion of the recommended dose in the United States is lower than coverage with other adolescent vaccinations, HPV vaccination is the best way to prevent HPV infections that can lead to several cancers in both females and males.”

The study was published online in Annals of Internal Medicine.
 

NHANES survey

The authors used data from the National Health and Nutrition Examination Survey (NHANES) to examine the four HPV types in the quadrivalent vaccine before 2003 and 2006 (the pre-vaccine era) and then again between 2007-2010, 2011-2014, and 2015-2018 (the vaccine era). For females, they analyzed demographic and HPV prevalence data across each 4-year era.

“Analyses were limited to sexually experienced participants, to ensure that all those included had an opportunity for HPV exposure, and to participants aged 14-24 years with adequate self-collected cervicovaginal specimens,” the authors explain.

This resulted in a sample size of 3,197 females. Demographic and HPV prevalence data were also collected from males but only during the 2013-2016 era, because those are the only years for which male HPV typing data are available in NHANES. Again, analyses were limited to sexually experienced males aged 14-24 years with adequate self-collected penile specimens, which resulted in a sample size of 661 males.

Over the 12 years of follow-up for females, there was a steady increase in females reporting having received at least one dose of the HPV vaccine – from slightly over 25% during 2007-12 to 59% during 2015-2018. The percentage of males who reported having at least one HPV dose also increased, from 29.5% in 2016 to 34.5% in 2018.

During the earliest vaccine era (2007-2010), the prevalence of the four HPV strains covered by the vaccine was 7.3% among vaccinated females, compared with 20.4% among unvaccinated females. “By 2015 to 2018, the prevalence was 2.8% (prevalence ratio, 0.16; 95% confidence interval, 0.07-0.39). The prevalence of the four vaccine-covered types was only 1.9% in vaccinated females, compared with 4.8% in unvaccinated females (PR, 0.40; 95% CI, 0.11-1.41).

In contrast, the prevalence of HPV types that were not covered by the vaccine showed little change – from 51.1% in the pre-vaccine era to 47.6% during 2015-2018 (PR, 0.93; 95% CI, 0.80-1.08). The authors considered this a good sign because it indicates that vaccine-type HPV infections are not being replaced with other oncogenic HPV infections. Between 2013 and 2016, the difference in the prevalence of the four HPV vaccine types was smaller at 1.8% among vaccinated males and 3.5% among unvaccinated males (PR, 0.49; 95% CI, 0.11-2.20).

Again, the prevalence of non-HPV vaccine types was not significantly different between vaccinated and unvaccinated males: 30.7% versus 34.3%.

During the vaccine era, effectiveness for females ranged from 60% to 84%. For males, vaccine effectiveness could only be evaluated for the single 4-year period from 2013 to 2016, and it was estimated at 51%. Dr. Rosenblum noted that vaccine efficacy estimates were lower on this national survey than the almost 100% efficacy rates observed in clinical trials in both males and females.

“This might be due in part to many participants receiving the vaccine at an older age than is recommended when they could have been infected [with HPV] at the time of vaccination,” Dr. Rosenblum said. She also noted that because males were incorporated into the HPV vaccination program years after females, they likely also experienced strong herd effects from the vaccine, making it challenging to estimate vaccine effectiveness.

Dr. Rosenblum also noted that there have already been documented declines in cervical precancers and high-grade vulvar and vaginal precancers, as well as genital warts and juvenile-onset recurrent respiratory papillomatosis. At the same time, the incidence of cervical precancers has recently declined among U.S. females in their late teens and early 20s – “likely reflecting the impact of vaccination,” she said.

“This study is good news for the United States HPV vaccination program, and all efforts are needed to ensure that children and adolescents receive routinely recommended vaccinations [including vaccination against HPV],” Dr. Rosenblum added.
 

Editorial comment

Commenting on the findings, Rebecca Perkins, MD, Boston University School of Medicine, and colleagues point out that the COVID-19 pandemic has led to disruptions in HPV vaccination programs and has reversed much of the progress made in recent years. “During the pandemic, providers and health systems have deprioritized adolescent vaccination and particularly HPV vaccination, which in turn has led to more severe drops for HPV vaccination than for other adolescent vaccinations, and for adolescent vaccination, compared with early childhood and adult vaccinations,” Dr. Perkins and colleagues write in an accompanying editorial.

Thus, the need to compensate for the cumulative deficit of missed vaccinations over the past 2 years has created a “serious and urgent threat” to cancer prevention efforts – “a shortfall from which it may take a decade to recover,” the editorialists predict. To try and reverse this trend, several practices have been shown to improve HPV vaccination rates.

The first is a strong provider recommendation such as, “Your child is due for an HPV vaccine today.” The second is to give standing orders to allow nurses and medical assistants to administer vaccinations without requiring intervention by a physician. Lastly, programs to remind patients when vaccines are due and to recall them for appointments also work well.

“Using evidence-based methods and redoubling our efforts to prioritize HPV vaccination will be crucial to ensuring that we do not lose a generation to preventable HPV-associated cancer,” write Dr. Perkins and colleagues.

The study authors and editorialists have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Twelve years after the human papillomavirus (HPV) vaccination program was introduced in the United States, the overall prevalence of cancer-causing HPV strains covered by the vaccine dropped by 85% among females – 90% among vaccinated females and 74% among unvaccinated females – a strong sign of herd immunity, a new analysis of a nationally representative database is showing.

“HPV vaccination is working well,” Hannah Rosenblum, MD, Centers for Disease Control and Prevention, Atlanta, told this news organization in an email.

“Twelve years after introduction of HPV vaccination in the United States, national data demonstrate increasing impact among females and strong herd effects among unvaccinated females,” she added. “[Although] vaccination coverage and completion of the recommended dose in the United States is lower than coverage with other adolescent vaccinations, HPV vaccination is the best way to prevent HPV infections that can lead to several cancers in both females and males.”

The study was published online in Annals of Internal Medicine.
 

NHANES survey

The authors used data from the National Health and Nutrition Examination Survey (NHANES) to examine the four HPV types in the quadrivalent vaccine before 2003 and 2006 (the pre-vaccine era) and then again between 2007-2010, 2011-2014, and 2015-2018 (the vaccine era). For females, they analyzed demographic and HPV prevalence data across each 4-year era.

“Analyses were limited to sexually experienced participants, to ensure that all those included had an opportunity for HPV exposure, and to participants aged 14-24 years with adequate self-collected cervicovaginal specimens,” the authors explain.

This resulted in a sample size of 3,197 females. Demographic and HPV prevalence data were also collected from males but only during the 2013-2016 era, because those are the only years for which male HPV typing data are available in NHANES. Again, analyses were limited to sexually experienced males aged 14-24 years with adequate self-collected penile specimens, which resulted in a sample size of 661 males.

Over the 12 years of follow-up for females, there was a steady increase in females reporting having received at least one dose of the HPV vaccine – from slightly over 25% during 2007-12 to 59% during 2015-2018. The percentage of males who reported having at least one HPV dose also increased, from 29.5% in 2016 to 34.5% in 2018.

During the earliest vaccine era (2007-2010), the prevalence of the four HPV strains covered by the vaccine was 7.3% among vaccinated females, compared with 20.4% among unvaccinated females. “By 2015 to 2018, the prevalence was 2.8% (prevalence ratio, 0.16; 95% confidence interval, 0.07-0.39). The prevalence of the four vaccine-covered types was only 1.9% in vaccinated females, compared with 4.8% in unvaccinated females (PR, 0.40; 95% CI, 0.11-1.41).

In contrast, the prevalence of HPV types that were not covered by the vaccine showed little change – from 51.1% in the pre-vaccine era to 47.6% during 2015-2018 (PR, 0.93; 95% CI, 0.80-1.08). The authors considered this a good sign because it indicates that vaccine-type HPV infections are not being replaced with other oncogenic HPV infections. Between 2013 and 2016, the difference in the prevalence of the four HPV vaccine types was smaller at 1.8% among vaccinated males and 3.5% among unvaccinated males (PR, 0.49; 95% CI, 0.11-2.20).

Again, the prevalence of non-HPV vaccine types was not significantly different between vaccinated and unvaccinated males: 30.7% versus 34.3%.

During the vaccine era, effectiveness for females ranged from 60% to 84%. For males, vaccine effectiveness could only be evaluated for the single 4-year period from 2013 to 2016, and it was estimated at 51%. Dr. Rosenblum noted that vaccine efficacy estimates were lower on this national survey than the almost 100% efficacy rates observed in clinical trials in both males and females.

“This might be due in part to many participants receiving the vaccine at an older age than is recommended when they could have been infected [with HPV] at the time of vaccination,” Dr. Rosenblum said. She also noted that because males were incorporated into the HPV vaccination program years after females, they likely also experienced strong herd effects from the vaccine, making it challenging to estimate vaccine effectiveness.

Dr. Rosenblum also noted that there have already been documented declines in cervical precancers and high-grade vulvar and vaginal precancers, as well as genital warts and juvenile-onset recurrent respiratory papillomatosis. At the same time, the incidence of cervical precancers has recently declined among U.S. females in their late teens and early 20s – “likely reflecting the impact of vaccination,” she said.

“This study is good news for the United States HPV vaccination program, and all efforts are needed to ensure that children and adolescents receive routinely recommended vaccinations [including vaccination against HPV],” Dr. Rosenblum added.
 

Editorial comment

Commenting on the findings, Rebecca Perkins, MD, Boston University School of Medicine, and colleagues point out that the COVID-19 pandemic has led to disruptions in HPV vaccination programs and has reversed much of the progress made in recent years. “During the pandemic, providers and health systems have deprioritized adolescent vaccination and particularly HPV vaccination, which in turn has led to more severe drops for HPV vaccination than for other adolescent vaccinations, and for adolescent vaccination, compared with early childhood and adult vaccinations,” Dr. Perkins and colleagues write in an accompanying editorial.

Thus, the need to compensate for the cumulative deficit of missed vaccinations over the past 2 years has created a “serious and urgent threat” to cancer prevention efforts – “a shortfall from which it may take a decade to recover,” the editorialists predict. To try and reverse this trend, several practices have been shown to improve HPV vaccination rates.

The first is a strong provider recommendation such as, “Your child is due for an HPV vaccine today.” The second is to give standing orders to allow nurses and medical assistants to administer vaccinations without requiring intervention by a physician. Lastly, programs to remind patients when vaccines are due and to recall them for appointments also work well.

“Using evidence-based methods and redoubling our efforts to prioritize HPV vaccination will be crucial to ensuring that we do not lose a generation to preventable HPV-associated cancer,” write Dr. Perkins and colleagues.

The study authors and editorialists have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The Pfizer-BioNTech mRNA vaccine (Comirnaty) showed a good safety profile with minimal short-term side effects and no negative impact on disease activity in a cohort of adolescents and young adults with rheumatic diseases, according to research presented at the annual scientific meeting of the Childhood Arthritis and Rheumatology Research Alliance, held virtually this year.

Only 3% of patients experience a severe transient adverse event, according to Merav Heshin-Bekenstein, MD, of Dana-Dwek Children’s Hospital at the Tel Aviv Sourasky Medical Center in Israel. The findings were published in Rheumatology.

Courtesy Dr. Heshin-Bekenstein

“We found that the mRNA Pfizer vaccine was immunogenic and induced an adequate humoral immune response in adolescent patients,” Dr. Heshin-Bekenstein told CARRA attendees. “It was definitely comparable to healthy controls and practically all patients were seropositive following the second vaccine, except for one patient with long-standing systemic sclerosis.”

The findings were not necessarily surprising but were encouraging to Melissa S. Oliver, MD, assistant professor of clinical pediatrics in the division of pediatric rheumatology at Indiana University, Indianapolis. Dr. Oliver wasn’t part of the study team.

“We know that the COVID vaccines in healthy adolescents have shown good efficacy with minimal side effects, and it’s good to see that this study showed that in those with rheumatic diseases on immunosuppressive therapy,” Dr. Oliver told this news organization.

Until now, the data on COVID-19 vaccines in teens with rheumatic illnesses has been limited, she said, so “many pediatric rheumatologists only have the data from adult studies to go on or personal experience with their own cohort of patients.”

But the high immunogenicity seen in the study was a pleasant surprise to Beth H. Rutstein, MD, assistant professor of clinical pediatrics in the division of rheumatology at Children’s Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania.

“I was both surprised and thrilled with Dr. Heshin-Bekenstein’s findings suggesting near-universal seroconversion for patients with rheumatic disease regardless of underlying diagnosis or immunomodulatory therapy regimen, as much of the adult data has suggested a poorer seroconversion rate” and lower antibody titers in adults with similar illnesses, Dr. Rutstein said in an interview.

The study “provides essential reassurance that vaccination against COVID-19 does not increase the risk of disease flare or worsen disease severity scores,” said Dr. Rutstein, who was not associated with the research. “Rather than speaking purely anecdotally with our patients and their families, we can refer to the science – which is always more reassuring for both our patients and ourselves.”
 

Study included diverse conditions and therapies

Risk factors for poor outcomes with COVID-19 in children include obesity, cardiovascular disease, chronic lung disease, diabetes, and asthma, Dr. Heshin-Bekenstein told CARRA attendees. Multisystem inflammatory syndrome in children (MIS-C) and long COVID are also potential complications of COVID-19 with less understood risk factors.

Although COVID-19 is most often mild in children, certain severe, systemic rheumatic diseases increase hospitalization risk, including systemic lupus erythematosus (SLE) and vasculitis. Evidence has also shown that COVID-19 infection increases the risk of disease flare in teens with juvenile-onset rheumatic diseases, so it’s “crucial to prevent COVID-19 disease in this population,” Dr. Heshin-Bekenstein said.

Her study therefore aimed to assess the safety and immunogenicity of the Pfizer mRNA vaccine for teens with juvenile-onset rheumatic diseases and those taking immunomodulatory medications. The international prospective multicenter study ran from April to November 2021 at three pediatric rheumatology clinics in Israel and one in Slovenia. Endpoints included short-term side effects, vaccination impact on clinical disease activity, immunogenicity at 2-9 weeks after the second dose, and, secondarily, efficacy against COVID-19 infection.

The 91 participants included adolescents aged 12-18 and young adults aged 18-21. Nearly half of the participants (46%) had juvenile idiopathic arthritis (JIA), and 14% had SLE. Other participants’ conditions included systemic vasculitis, idiopathic uveitis, inflammatory bowel disease–related arthritis, systemic or localized scleroderma, juvenile dermatomyositis, or an autoinflammatory disease. Participants’ mean disease duration was 4.8 years.  

The researchers compared the patients with a control group of 40 individuals with similar demographics but without rheumatic disease. The researchers used the LIAISON quantitative assay to assess serum IgG antibody levels against the SARS-CoV-2 spike protein in both groups.

Eight in 10 participants with rheumatic disease were taking an immunomodulatory medication, including a conventional synthetic disease-modifying antirheumatic drug (csDMARD) in 40%, a biologic DMARD in 37%, tumor necrosis factor (TNF) inhibitors in 32%, hydroxychloroquine (HCQ) in 19%, glucocorticoids in 14%, and mycophenolate in 11%. A smaller proportion were on other biologics: JAK inhibitors in 6.6%, anti-CD20 drugs in 4.4%, and an IL-6 inhibitor in 1%.
 

Side effects similar in both groups

None of the side effects reported by participants were statistically different between those with rheumatic disease and the control group. Localized pain was the most common side effect, reported by 73%-79% of participants after each dose. About twice as many participants with rheumatic disease experienced muscle aches and joint pains, compared with the control group, but the differences were not significant. Fever occurred more often in those with rheumatic disease (6%, five cases) than without (3%, one case). One-third of those with rheumatic disease felt tiredness, compared with 20% of the control group.

None of the healthy controls were hospitalized after vaccination, but three rheumatic patients were, including two after the first dose. Both were 17 years old, had systemic vasculitis with granulomatosis with polyangiitis (GPA), and were taking rituximab (Rituxan). One patient experienced acute onset of chronic renal failure, fever, dehydration, and high C-reactive protein within hours of vaccination. The other experienced new onset of pulmonary hemorrhage a week after vaccination.

In addition, a 14-year-old female with lupus, taking only HCQ, went to the emergency department with fever, headache, vomiting, and joint pain 1 day after the second vaccine dose. She had normal inflammatory markers and no change in disease activity score, and she was discharged with low-dose steroids tapered after 2 weeks.
 

Immune response high in patients with rheumatic disease

Immunogenicity was similar in both groups, with 97% seropositivity in the rheumatic disease group and 100% in the control group. Average IgG titers were 242 in the rheumatic group and 388 in the control group (P < .0001). Seropositivity was 88% in those taking mycophenolate with another drug (100% with mycophenolate monotherapy), 90% with HCQ, 94% with any csDMARDs and another drug (100% with csDMARD monotherapy), and 100% for all other drugs. During 3 months’ follow-up after vaccination, there were no COVID-19 cases among the participants.

Dr. Heshin-Bekenstein noted that their results showed better immunogenicity in teens, compared with adults, for two specific drugs. Seropositivity in teens taking methotrexate (Rheumatrex, Trexall) or rituximab was 100% in this study, compared with 84% in adults taking methotrexate and 39% in adults taking rituximab in a previous study. However, only three patients in this study were taking rituximab, and only seven were taking methotrexate.

The study’s heterogenous population was both a strength and a weakness of the study. “Due to the diversity of rheumatic diseases and medications included in this cohort, it was not possible to draw significant conclusions regarding the impact of the immunomodulatory medications and type of disease” on titers, Dr. Heshin-Bekenstein told attendees.

Still, “I think as pediatric rheumatologists, we can feel reassured in recommending the COVID-19 vaccine to our patients,” Dr. Oliver said. “I will add that every patient is different, and everyone should have a conversation with their physician about receiving the COVID-19 vaccine.” Dr. Oliver said she discusses vaccination, including COVID vaccination, with every patient, and it’s been challenging to address concerns in the midst of so much misinformation circulating about the vaccine.

These findings do raise questions about whether it’s still necessary to hold immunomodulatory medications to get the vaccine,” Dr. Rutstein said.

“Many families are nervous to pause their medications before and after the vaccine as is currently recommended for many therapies by the American College of Rheumatology, and I do share that concern for some of my patients with more clinically unstable disease, so I try to work with each family to decide on best timing and have delayed or deferred the series until some patients are on a steady dose of a new immunomodulatory medication if it has been recently started,” Dr. Rutstein said. “This is one of the reasons why Dr. Heshin-Bekenstein’s study is so important – we may be holding medications that can be safely continued and even further decrease the risk of disease flare.”

None of the physicians have disclosed any relevant financial relationships.

A version of this article first appeared on Medscape.com.

The Pfizer-BioNTech mRNA vaccine (Comirnaty) showed a good safety profile with minimal short-term side effects and no negative impact on disease activity in a cohort of adolescents and young adults with rheumatic diseases, according to research presented at the annual scientific meeting of the Childhood Arthritis and Rheumatology Research Alliance, held virtually this year.

Only 3% of patients experience a severe transient adverse event, according to Merav Heshin-Bekenstein, MD, of Dana-Dwek Children’s Hospital at the Tel Aviv Sourasky Medical Center in Israel. The findings were published in Rheumatology.

Courtesy Dr. Heshin-Bekenstein

“We found that the mRNA Pfizer vaccine was immunogenic and induced an adequate humoral immune response in adolescent patients,” Dr. Heshin-Bekenstein told CARRA attendees. “It was definitely comparable to healthy controls and practically all patients were seropositive following the second vaccine, except for one patient with long-standing systemic sclerosis.”

The findings were not necessarily surprising but were encouraging to Melissa S. Oliver, MD, assistant professor of clinical pediatrics in the division of pediatric rheumatology at Indiana University, Indianapolis. Dr. Oliver wasn’t part of the study team.

“We know that the COVID vaccines in healthy adolescents have shown good efficacy with minimal side effects, and it’s good to see that this study showed that in those with rheumatic diseases on immunosuppressive therapy,” Dr. Oliver told this news organization.

Until now, the data on COVID-19 vaccines in teens with rheumatic illnesses has been limited, she said, so “many pediatric rheumatologists only have the data from adult studies to go on or personal experience with their own cohort of patients.”

But the high immunogenicity seen in the study was a pleasant surprise to Beth H. Rutstein, MD, assistant professor of clinical pediatrics in the division of rheumatology at Children’s Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania.

“I was both surprised and thrilled with Dr. Heshin-Bekenstein’s findings suggesting near-universal seroconversion for patients with rheumatic disease regardless of underlying diagnosis or immunomodulatory therapy regimen, as much of the adult data has suggested a poorer seroconversion rate” and lower antibody titers in adults with similar illnesses, Dr. Rutstein said in an interview.

The study “provides essential reassurance that vaccination against COVID-19 does not increase the risk of disease flare or worsen disease severity scores,” said Dr. Rutstein, who was not associated with the research. “Rather than speaking purely anecdotally with our patients and their families, we can refer to the science – which is always more reassuring for both our patients and ourselves.”
 

Study included diverse conditions and therapies

Risk factors for poor outcomes with COVID-19 in children include obesity, cardiovascular disease, chronic lung disease, diabetes, and asthma, Dr. Heshin-Bekenstein told CARRA attendees. Multisystem inflammatory syndrome in children (MIS-C) and long COVID are also potential complications of COVID-19 with less understood risk factors.

Although COVID-19 is most often mild in children, certain severe, systemic rheumatic diseases increase hospitalization risk, including systemic lupus erythematosus (SLE) and vasculitis. Evidence has also shown that COVID-19 infection increases the risk of disease flare in teens with juvenile-onset rheumatic diseases, so it’s “crucial to prevent COVID-19 disease in this population,” Dr. Heshin-Bekenstein said.

Her study therefore aimed to assess the safety and immunogenicity of the Pfizer mRNA vaccine for teens with juvenile-onset rheumatic diseases and those taking immunomodulatory medications. The international prospective multicenter study ran from April to November 2021 at three pediatric rheumatology clinics in Israel and one in Slovenia. Endpoints included short-term side effects, vaccination impact on clinical disease activity, immunogenicity at 2-9 weeks after the second dose, and, secondarily, efficacy against COVID-19 infection.

The 91 participants included adolescents aged 12-18 and young adults aged 18-21. Nearly half of the participants (46%) had juvenile idiopathic arthritis (JIA), and 14% had SLE. Other participants’ conditions included systemic vasculitis, idiopathic uveitis, inflammatory bowel disease–related arthritis, systemic or localized scleroderma, juvenile dermatomyositis, or an autoinflammatory disease. Participants’ mean disease duration was 4.8 years.  

The researchers compared the patients with a control group of 40 individuals with similar demographics but without rheumatic disease. The researchers used the LIAISON quantitative assay to assess serum IgG antibody levels against the SARS-CoV-2 spike protein in both groups.

Eight in 10 participants with rheumatic disease were taking an immunomodulatory medication, including a conventional synthetic disease-modifying antirheumatic drug (csDMARD) in 40%, a biologic DMARD in 37%, tumor necrosis factor (TNF) inhibitors in 32%, hydroxychloroquine (HCQ) in 19%, glucocorticoids in 14%, and mycophenolate in 11%. A smaller proportion were on other biologics: JAK inhibitors in 6.6%, anti-CD20 drugs in 4.4%, and an IL-6 inhibitor in 1%.
 

Side effects similar in both groups

None of the side effects reported by participants were statistically different between those with rheumatic disease and the control group. Localized pain was the most common side effect, reported by 73%-79% of participants after each dose. About twice as many participants with rheumatic disease experienced muscle aches and joint pains, compared with the control group, but the differences were not significant. Fever occurred more often in those with rheumatic disease (6%, five cases) than without (3%, one case). One-third of those with rheumatic disease felt tiredness, compared with 20% of the control group.

None of the healthy controls were hospitalized after vaccination, but three rheumatic patients were, including two after the first dose. Both were 17 years old, had systemic vasculitis with granulomatosis with polyangiitis (GPA), and were taking rituximab (Rituxan). One patient experienced acute onset of chronic renal failure, fever, dehydration, and high C-reactive protein within hours of vaccination. The other experienced new onset of pulmonary hemorrhage a week after vaccination.

In addition, a 14-year-old female with lupus, taking only HCQ, went to the emergency department with fever, headache, vomiting, and joint pain 1 day after the second vaccine dose. She had normal inflammatory markers and no change in disease activity score, and she was discharged with low-dose steroids tapered after 2 weeks.
 

Immune response high in patients with rheumatic disease

Immunogenicity was similar in both groups, with 97% seropositivity in the rheumatic disease group and 100% in the control group. Average IgG titers were 242 in the rheumatic group and 388 in the control group (P < .0001). Seropositivity was 88% in those taking mycophenolate with another drug (100% with mycophenolate monotherapy), 90% with HCQ, 94% with any csDMARDs and another drug (100% with csDMARD monotherapy), and 100% for all other drugs. During 3 months’ follow-up after vaccination, there were no COVID-19 cases among the participants.

Dr. Heshin-Bekenstein noted that their results showed better immunogenicity in teens, compared with adults, for two specific drugs. Seropositivity in teens taking methotrexate (Rheumatrex, Trexall) or rituximab was 100% in this study, compared with 84% in adults taking methotrexate and 39% in adults taking rituximab in a previous study. However, only three patients in this study were taking rituximab, and only seven were taking methotrexate.

The study’s heterogenous population was both a strength and a weakness of the study. “Due to the diversity of rheumatic diseases and medications included in this cohort, it was not possible to draw significant conclusions regarding the impact of the immunomodulatory medications and type of disease” on titers, Dr. Heshin-Bekenstein told attendees.

Still, “I think as pediatric rheumatologists, we can feel reassured in recommending the COVID-19 vaccine to our patients,” Dr. Oliver said. “I will add that every patient is different, and everyone should have a conversation with their physician about receiving the COVID-19 vaccine.” Dr. Oliver said she discusses vaccination, including COVID vaccination, with every patient, and it’s been challenging to address concerns in the midst of so much misinformation circulating about the vaccine.

These findings do raise questions about whether it’s still necessary to hold immunomodulatory medications to get the vaccine,” Dr. Rutstein said.

“Many families are nervous to pause their medications before and after the vaccine as is currently recommended for many therapies by the American College of Rheumatology, and I do share that concern for some of my patients with more clinically unstable disease, so I try to work with each family to decide on best timing and have delayed or deferred the series until some patients are on a steady dose of a new immunomodulatory medication if it has been recently started,” Dr. Rutstein said. “This is one of the reasons why Dr. Heshin-Bekenstein’s study is so important – we may be holding medications that can be safely continued and even further decrease the risk of disease flare.”

None of the physicians have disclosed any relevant financial relationships.

A version of this article first appeared on Medscape.com.

The Pfizer-BioNTech mRNA vaccine (Comirnaty) showed a good safety profile with minimal short-term side effects and no negative impact on disease activity in a cohort of adolescents and young adults with rheumatic diseases, according to research presented at the annual scientific meeting of the Childhood Arthritis and Rheumatology Research Alliance, held virtually this year.

Only 3% of patients experience a severe transient adverse event, according to Merav Heshin-Bekenstein, MD, of Dana-Dwek Children’s Hospital at the Tel Aviv Sourasky Medical Center in Israel. The findings were published in Rheumatology.

Courtesy Dr. Heshin-Bekenstein

“We found that the mRNA Pfizer vaccine was immunogenic and induced an adequate humoral immune response in adolescent patients,” Dr. Heshin-Bekenstein told CARRA attendees. “It was definitely comparable to healthy controls and practically all patients were seropositive following the second vaccine, except for one patient with long-standing systemic sclerosis.”

The findings were not necessarily surprising but were encouraging to Melissa S. Oliver, MD, assistant professor of clinical pediatrics in the division of pediatric rheumatology at Indiana University, Indianapolis. Dr. Oliver wasn’t part of the study team.

“We know that the COVID vaccines in healthy adolescents have shown good efficacy with minimal side effects, and it’s good to see that this study showed that in those with rheumatic diseases on immunosuppressive therapy,” Dr. Oliver told this news organization.

Until now, the data on COVID-19 vaccines in teens with rheumatic illnesses has been limited, she said, so “many pediatric rheumatologists only have the data from adult studies to go on or personal experience with their own cohort of patients.”

But the high immunogenicity seen in the study was a pleasant surprise to Beth H. Rutstein, MD, assistant professor of clinical pediatrics in the division of rheumatology at Children’s Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania.

“I was both surprised and thrilled with Dr. Heshin-Bekenstein’s findings suggesting near-universal seroconversion for patients with rheumatic disease regardless of underlying diagnosis or immunomodulatory therapy regimen, as much of the adult data has suggested a poorer seroconversion rate” and lower antibody titers in adults with similar illnesses, Dr. Rutstein said in an interview.

The study “provides essential reassurance that vaccination against COVID-19 does not increase the risk of disease flare or worsen disease severity scores,” said Dr. Rutstein, who was not associated with the research. “Rather than speaking purely anecdotally with our patients and their families, we can refer to the science – which is always more reassuring for both our patients and ourselves.”
 

Study included diverse conditions and therapies

Risk factors for poor outcomes with COVID-19 in children include obesity, cardiovascular disease, chronic lung disease, diabetes, and asthma, Dr. Heshin-Bekenstein told CARRA attendees. Multisystem inflammatory syndrome in children (MIS-C) and long COVID are also potential complications of COVID-19 with less understood risk factors.

Although COVID-19 is most often mild in children, certain severe, systemic rheumatic diseases increase hospitalization risk, including systemic lupus erythematosus (SLE) and vasculitis. Evidence has also shown that COVID-19 infection increases the risk of disease flare in teens with juvenile-onset rheumatic diseases, so it’s “crucial to prevent COVID-19 disease in this population,” Dr. Heshin-Bekenstein said.

Her study therefore aimed to assess the safety and immunogenicity of the Pfizer mRNA vaccine for teens with juvenile-onset rheumatic diseases and those taking immunomodulatory medications. The international prospective multicenter study ran from April to November 2021 at three pediatric rheumatology clinics in Israel and one in Slovenia. Endpoints included short-term side effects, vaccination impact on clinical disease activity, immunogenicity at 2-9 weeks after the second dose, and, secondarily, efficacy against COVID-19 infection.

The 91 participants included adolescents aged 12-18 and young adults aged 18-21. Nearly half of the participants (46%) had juvenile idiopathic arthritis (JIA), and 14% had SLE. Other participants’ conditions included systemic vasculitis, idiopathic uveitis, inflammatory bowel disease–related arthritis, systemic or localized scleroderma, juvenile dermatomyositis, or an autoinflammatory disease. Participants’ mean disease duration was 4.8 years.  

The researchers compared the patients with a control group of 40 individuals with similar demographics but without rheumatic disease. The researchers used the LIAISON quantitative assay to assess serum IgG antibody levels against the SARS-CoV-2 spike protein in both groups.

Eight in 10 participants with rheumatic disease were taking an immunomodulatory medication, including a conventional synthetic disease-modifying antirheumatic drug (csDMARD) in 40%, a biologic DMARD in 37%, tumor necrosis factor (TNF) inhibitors in 32%, hydroxychloroquine (HCQ) in 19%, glucocorticoids in 14%, and mycophenolate in 11%. A smaller proportion were on other biologics: JAK inhibitors in 6.6%, anti-CD20 drugs in 4.4%, and an IL-6 inhibitor in 1%.
 

Side effects similar in both groups

None of the side effects reported by participants were statistically different between those with rheumatic disease and the control group. Localized pain was the most common side effect, reported by 73%-79% of participants after each dose. About twice as many participants with rheumatic disease experienced muscle aches and joint pains, compared with the control group, but the differences were not significant. Fever occurred more often in those with rheumatic disease (6%, five cases) than without (3%, one case). One-third of those with rheumatic disease felt tiredness, compared with 20% of the control group.

None of the healthy controls were hospitalized after vaccination, but three rheumatic patients were, including two after the first dose. Both were 17 years old, had systemic vasculitis with granulomatosis with polyangiitis (GPA), and were taking rituximab (Rituxan). One patient experienced acute onset of chronic renal failure, fever, dehydration, and high C-reactive protein within hours of vaccination. The other experienced new onset of pulmonary hemorrhage a week after vaccination.

In addition, a 14-year-old female with lupus, taking only HCQ, went to the emergency department with fever, headache, vomiting, and joint pain 1 day after the second vaccine dose. She had normal inflammatory markers and no change in disease activity score, and she was discharged with low-dose steroids tapered after 2 weeks.
 

Immune response high in patients with rheumatic disease

Immunogenicity was similar in both groups, with 97% seropositivity in the rheumatic disease group and 100% in the control group. Average IgG titers were 242 in the rheumatic group and 388 in the control group (P < .0001). Seropositivity was 88% in those taking mycophenolate with another drug (100% with mycophenolate monotherapy), 90% with HCQ, 94% with any csDMARDs and another drug (100% with csDMARD monotherapy), and 100% for all other drugs. During 3 months’ follow-up after vaccination, there were no COVID-19 cases among the participants.

Dr. Heshin-Bekenstein noted that their results showed better immunogenicity in teens, compared with adults, for two specific drugs. Seropositivity in teens taking methotrexate (Rheumatrex, Trexall) or rituximab was 100% in this study, compared with 84% in adults taking methotrexate and 39% in adults taking rituximab in a previous study. However, only three patients in this study were taking rituximab, and only seven were taking methotrexate.

The study’s heterogenous population was both a strength and a weakness of the study. “Due to the diversity of rheumatic diseases and medications included in this cohort, it was not possible to draw significant conclusions regarding the impact of the immunomodulatory medications and type of disease” on titers, Dr. Heshin-Bekenstein told attendees.

Still, “I think as pediatric rheumatologists, we can feel reassured in recommending the COVID-19 vaccine to our patients,” Dr. Oliver said. “I will add that every patient is different, and everyone should have a conversation with their physician about receiving the COVID-19 vaccine.” Dr. Oliver said she discusses vaccination, including COVID vaccination, with every patient, and it’s been challenging to address concerns in the midst of so much misinformation circulating about the vaccine.

These findings do raise questions about whether it’s still necessary to hold immunomodulatory medications to get the vaccine,” Dr. Rutstein said.

“Many families are nervous to pause their medications before and after the vaccine as is currently recommended for many therapies by the American College of Rheumatology, and I do share that concern for some of my patients with more clinically unstable disease, so I try to work with each family to decide on best timing and have delayed or deferred the series until some patients are on a steady dose of a new immunomodulatory medication if it has been recently started,” Dr. Rutstein said. “This is one of the reasons why Dr. Heshin-Bekenstein’s study is so important – we may be holding medications that can be safely continued and even further decrease the risk of disease flare.”

None of the physicians have disclosed any relevant financial relationships.

A version of this article first appeared on Medscape.com.

The U.S. immunization program is one of the best public health success stories. Physicians who provide care for children are familiar with the routine childhood immunization schedule and administer a measles-containing vaccine at age-appropriate times. Thanks to its rigorous implementation and acceptance, endemic measles (absence of continuous virus transmission for > 1 year) was eliminated in the U.S. in 2000. Loss of this status was in jeopardy in 2019 when 22 measles outbreaks occurred in 17 states (7 were multistate outbreaks). That year, 1,163 cases were reported.¹ Most cases occurred in unvaccinated persons (89%) and 81 cases were imported of which 54 were in U.S. citizens returning from international travel. All outbreaks were linked to travel. Fortunately, the outbreaks were controlled prior to the elimination deadline, or the United States would have lost its measles elimination status. Restrictions on travel because of COVID-19 have relaxed significantly since the introduction of COVID-19 vaccines, resulting in increased regional and international travel. Multiple countries, including the United States noted a decline in routine immunizations rates during the last 2 years. Recent U.S. data for the 2020-2021 school year indicates that MMR immunizations rates (two doses) for kindergarteners declined to 93.9% (range 78.9% to > 98.9%), while the overall percentage of those students with an exemption remained low at 2.2%. Vaccine coverage greater than 95% was reported in only 16 states. Coverage of less than 90% was reported in seven states and the District of Columbia (Georgia, Idaho, Kentucky, Maryland, Minnesota, Ohio, and Wisconsin).² Vaccine coverage should be 95% or higher to maintain herd immunity and control outbreaks.

Why is measles prevention so important? Many physicians practicing in the United States today have never seen a case or know its potential complications. I saw my first case as a resident in an immigrant child. It took our training director to point out the subtle signs and symptoms. It was the first time I saw Kolpik spots. Measles is transmitted person to person via large respiratory droplets and less often by airborne spread. It is highly contagious for susceptible individuals with an attack rate of 90%. In this case, a medical student on the team developed symptoms about 10 days later. Six years would pass before I diagnosed my next case of measles. An HIV patient acquired it after close contact with someone who was in the prodromal stage. He presented with the 3 C’s: Cough, coryza, and conjunctivitis, in addition to fever and an erythematous rash. He did not recover from complications of the disease.

Prior to the routine administration of a measles vaccine, 3-4 million cases with almost 500 deaths occurred annually in the United States. Worldwide, 35 million cases and more than 6 million deaths occurred each year. Here, most patients recover completely; however, complications including otitis media, pneumonia, croup, and encephalitis can develop. Complications commonly occur in immunocompromised individuals and young children. Groups with the highest fatality rates include children aged less than 5 years, immunocompromised persons, and pregnant women. Worldwide, fatality rates are dependent on the patients underlying nutritional and health status in addition to the quality of health care available.³

Measles vaccine was licensed in 1963 and cases began to decline (Figure 1). There was a resurgence in 1989 but it was not limited to the United States. The cause of the U.S. resurgence was multifactorial: Widespread viral transmission among unvaccinated preschool-age children residing in inner cities, outbreaks in vaccinated school-age children, outbreaks in students and personnel on college campuses, and primary vaccine failure (2%-5% of recipients failed to have an adequate response). In 1989, to help prevent future outbreaks, the United States recommended a two-dose schedule for measles and in 1993, the Vaccines for Children Program, a federally funded program, was established to improve access to vaccines for all children.
 

What is going on internationally?

Figure 2 lists the top 10 countries with current measles outbreaks.

Most countries on the list may not be typical travel destinations for tourists; however, they are common destinations for individuals visiting friends and relatives after immigrating to the United States. In contrast to the United States, most countries with limited resources and infrastructure have mass-vaccination campaigns to ensure vaccine administration to large segments of the population. They too have been affected by the COVID-19 pandemic. By report, at least 41 countries delayed implementation of their measles campaign in 2020 and 2021, thus, leading to the potential for even larger outbreaks.⁴

Progress toward the global elimination of measles is evidenced by the following: All 194 countries now include one dose of measles in their routine schedules; between 2000 and 2019 coverage of one dose of measles increased from 72% to 85% and countries with more than 90% coverage increased from 45% to 63%. Finally, the number of countries offering two doses of measles increased from 50% to 91% and vaccine coverage increased from 18% to 71% over the same time period.³

What can you do for your patients and their parents before they travel abroad?

• Inform all staff that the MMR vaccine can be administered to children as young as 6 months and at times other than those listed on the routine immunization schedule. This will help avoid parents seeking vaccine being denied an appointment.
• Children 6-11 months need 1 dose of MMR. Two additional doses will still need to be administered at the routine time.
• Children 12 months or older need 2 doses of MMR at least 4 weeks apart.
• If yellow fever vaccine is needed, coordinate administration with a travel medicine clinic since both are live vaccines and must be given on the same day.
• Any person born after 1956 should have 2 doses of MMR at least 4 weeks apart if they have no evidence of immunity.
• Encourage parents to always inform you and your staff of any international travel plans.

Moving forward, remember this increased global activity and the presence of inadequately vaccinated individuals/communities keeps the United States at continued risk for measles outbreaks. The source of the next outbreak may only be one plane ride away.

Dr. Word is a pediatric infectious disease specialist and director of the Houston Travel Medicine Clinic. She said she had no relevant financial disclosures.

This article was updated 6/29/22.

References

1. Patel M et al. MMWR. 2019 Oct 11; 68(40):893-6.

2. Seither R et al. MMWR. 2022 Apr 22;71(16):561-8.

3. Gastañaduy PA et al. J Infect Dis. 2021 Sep 30;224(12 Suppl 2):S420-8. doi: 10.1093/infdis/jiaa793.

4. Centers for Disease Control and Prevention. Measles (Rubeola). http://www.CDC.gov/Measles.

The U.S. immunization program is one of the best public health success stories. Physicians who provide care for children are familiar with the routine childhood immunization schedule and administer a measles-containing vaccine at age-appropriate times. Thanks to its rigorous implementation and acceptance, endemic measles (absence of continuous virus transmission for > 1 year) was eliminated in the U.S. in 2000. Loss of this status was in jeopardy in 2019 when 22 measles outbreaks occurred in 17 states (7 were multistate outbreaks). That year, 1,163 cases were reported.¹ Most cases occurred in unvaccinated persons (89%) and 81 cases were imported of which 54 were in U.S. citizens returning from international travel. All outbreaks were linked to travel. Fortunately, the outbreaks were controlled prior to the elimination deadline, or the United States would have lost its measles elimination status. Restrictions on travel because of COVID-19 have relaxed significantly since the introduction of COVID-19 vaccines, resulting in increased regional and international travel. Multiple countries, including the United States noted a decline in routine immunizations rates during the last 2 years. Recent U.S. data for the 2020-2021 school year indicates that MMR immunizations rates (two doses) for kindergarteners declined to 93.9% (range 78.9% to > 98.9%), while the overall percentage of those students with an exemption remained low at 2.2%. Vaccine coverage greater than 95% was reported in only 16 states. Coverage of less than 90% was reported in seven states and the District of Columbia (Georgia, Idaho, Kentucky, Maryland, Minnesota, Ohio, and Wisconsin).² Vaccine coverage should be 95% or higher to maintain herd immunity and control outbreaks.

Why is measles prevention so important? Many physicians practicing in the United States today have never seen a case or know its potential complications. I saw my first case as a resident in an immigrant child. It took our training director to point out the subtle signs and symptoms. It was the first time I saw Kolpik spots. Measles is transmitted person to person via large respiratory droplets and less often by airborne spread. It is highly contagious for susceptible individuals with an attack rate of 90%. In this case, a medical student on the team developed symptoms about 10 days later. Six years would pass before I diagnosed my next case of measles. An HIV patient acquired it after close contact with someone who was in the prodromal stage. He presented with the 3 C’s: Cough, coryza, and conjunctivitis, in addition to fever and an erythematous rash. He did not recover from complications of the disease.

Prior to the routine administration of a measles vaccine, 3-4 million cases with almost 500 deaths occurred annually in the United States. Worldwide, 35 million cases and more than 6 million deaths occurred each year. Here, most patients recover completely; however, complications including otitis media, pneumonia, croup, and encephalitis can develop. Complications commonly occur in immunocompromised individuals and young children. Groups with the highest fatality rates include children aged less than 5 years, immunocompromised persons, and pregnant women. Worldwide, fatality rates are dependent on the patients underlying nutritional and health status in addition to the quality of health care available.³

Measles vaccine was licensed in 1963 and cases began to decline (Figure 1). There was a resurgence in 1989 but it was not limited to the United States. The cause of the U.S. resurgence was multifactorial: Widespread viral transmission among unvaccinated preschool-age children residing in inner cities, outbreaks in vaccinated school-age children, outbreaks in students and personnel on college campuses, and primary vaccine failure (2%-5% of recipients failed to have an adequate response). In 1989, to help prevent future outbreaks, the United States recommended a two-dose schedule for measles and in 1993, the Vaccines for Children Program, a federally funded program, was established to improve access to vaccines for all children.
 

What is going on internationally?

Figure 2 lists the top 10 countries with current measles outbreaks.

Most countries on the list may not be typical travel destinations for tourists; however, they are common destinations for individuals visiting friends and relatives after immigrating to the United States. In contrast to the United States, most countries with limited resources and infrastructure have mass-vaccination campaigns to ensure vaccine administration to large segments of the population. They too have been affected by the COVID-19 pandemic. By report, at least 41 countries delayed implementation of their measles campaign in 2020 and 2021, thus, leading to the potential for even larger outbreaks.⁴

Progress toward the global elimination of measles is evidenced by the following: All 194 countries now include one dose of measles in their routine schedules; between 2000 and 2019 coverage of one dose of measles increased from 72% to 85% and countries with more than 90% coverage increased from 45% to 63%. Finally, the number of countries offering two doses of measles increased from 50% to 91% and vaccine coverage increased from 18% to 71% over the same time period.³

What can you do for your patients and their parents before they travel abroad?

• Inform all staff that the MMR vaccine can be administered to children as young as 6 months and at times other than those listed on the routine immunization schedule. This will help avoid parents seeking vaccine being denied an appointment.
• Children 6-11 months need 1 dose of MMR. Two additional doses will still need to be administered at the routine time.
• Children 12 months or older need 2 doses of MMR at least 4 weeks apart.
• If yellow fever vaccine is needed, coordinate administration with a travel medicine clinic since both are live vaccines and must be given on the same day.
• Any person born after 1956 should have 2 doses of MMR at least 4 weeks apart if they have no evidence of immunity.
• Encourage parents to always inform you and your staff of any international travel plans.

Moving forward, remember this increased global activity and the presence of inadequately vaccinated individuals/communities keeps the United States at continued risk for measles outbreaks. The source of the next outbreak may only be one plane ride away.

Dr. Word is a pediatric infectious disease specialist and director of the Houston Travel Medicine Clinic. She said she had no relevant financial disclosures.

This article was updated 6/29/22.

References

1. Patel M et al. MMWR. 2019 Oct 11; 68(40):893-6.

2. Seither R et al. MMWR. 2022 Apr 22;71(16):561-8.

3. Gastañaduy PA et al. J Infect Dis. 2021 Sep 30;224(12 Suppl 2):S420-8. doi: 10.1093/infdis/jiaa793.

4. Centers for Disease Control and Prevention. Measles (Rubeola). http://www.CDC.gov/Measles.

The U.S. immunization program is one of the best public health success stories. Physicians who provide care for children are familiar with the routine childhood immunization schedule and administer a measles-containing vaccine at age-appropriate times. Thanks to its rigorous implementation and acceptance, endemic measles (absence of continuous virus transmission for > 1 year) was eliminated in the U.S. in 2000. Loss of this status was in jeopardy in 2019 when 22 measles outbreaks occurred in 17 states (7 were multistate outbreaks). That year, 1,163 cases were reported.¹ Most cases occurred in unvaccinated persons (89%) and 81 cases were imported of which 54 were in U.S. citizens returning from international travel. All outbreaks were linked to travel. Fortunately, the outbreaks were controlled prior to the elimination deadline, or the United States would have lost its measles elimination status. Restrictions on travel because of COVID-19 have relaxed significantly since the introduction of COVID-19 vaccines, resulting in increased regional and international travel. Multiple countries, including the United States noted a decline in routine immunizations rates during the last 2 years. Recent U.S. data for the 2020-2021 school year indicates that MMR immunizations rates (two doses) for kindergarteners declined to 93.9% (range 78.9% to > 98.9%), while the overall percentage of those students with an exemption remained low at 2.2%. Vaccine coverage greater than 95% was reported in only 16 states. Coverage of less than 90% was reported in seven states and the District of Columbia (Georgia, Idaho, Kentucky, Maryland, Minnesota, Ohio, and Wisconsin).² Vaccine coverage should be 95% or higher to maintain herd immunity and control outbreaks.

Why is measles prevention so important? Many physicians practicing in the United States today have never seen a case or know its potential complications. I saw my first case as a resident in an immigrant child. It took our training director to point out the subtle signs and symptoms. It was the first time I saw Kolpik spots. Measles is transmitted person to person via large respiratory droplets and less often by airborne spread. It is highly contagious for susceptible individuals with an attack rate of 90%. In this case, a medical student on the team developed symptoms about 10 days later. Six years would pass before I diagnosed my next case of measles. An HIV patient acquired it after close contact with someone who was in the prodromal stage. He presented with the 3 C’s: Cough, coryza, and conjunctivitis, in addition to fever and an erythematous rash. He did not recover from complications of the disease.

Prior to the routine administration of a measles vaccine, 3-4 million cases with almost 500 deaths occurred annually in the United States. Worldwide, 35 million cases and more than 6 million deaths occurred each year. Here, most patients recover completely; however, complications including otitis media, pneumonia, croup, and encephalitis can develop. Complications commonly occur in immunocompromised individuals and young children. Groups with the highest fatality rates include children aged less than 5 years, immunocompromised persons, and pregnant women. Worldwide, fatality rates are dependent on the patients underlying nutritional and health status in addition to the quality of health care available.³

Measles vaccine was licensed in 1963 and cases began to decline (Figure 1). There was a resurgence in 1989 but it was not limited to the United States. The cause of the U.S. resurgence was multifactorial: Widespread viral transmission among unvaccinated preschool-age children residing in inner cities, outbreaks in vaccinated school-age children, outbreaks in students and personnel on college campuses, and primary vaccine failure (2%-5% of recipients failed to have an adequate response). In 1989, to help prevent future outbreaks, the United States recommended a two-dose schedule for measles and in 1993, the Vaccines for Children Program, a federally funded program, was established to improve access to vaccines for all children.
 

What is going on internationally?

Figure 2 lists the top 10 countries with current measles outbreaks.

Most countries on the list may not be typical travel destinations for tourists; however, they are common destinations for individuals visiting friends and relatives after immigrating to the United States. In contrast to the United States, most countries with limited resources and infrastructure have mass-vaccination campaigns to ensure vaccine administration to large segments of the population. They too have been affected by the COVID-19 pandemic. By report, at least 41 countries delayed implementation of their measles campaign in 2020 and 2021, thus, leading to the potential for even larger outbreaks.⁴

Progress toward the global elimination of measles is evidenced by the following: All 194 countries now include one dose of measles in their routine schedules; between 2000 and 2019 coverage of one dose of measles increased from 72% to 85% and countries with more than 90% coverage increased from 45% to 63%. Finally, the number of countries offering two doses of measles increased from 50% to 91% and vaccine coverage increased from 18% to 71% over the same time period.³

What can you do for your patients and their parents before they travel abroad?

• Inform all staff that the MMR vaccine can be administered to children as young as 6 months and at times other than those listed on the routine immunization schedule. This will help avoid parents seeking vaccine being denied an appointment.
• Children 6-11 months need 1 dose of MMR. Two additional doses will still need to be administered at the routine time.
• Children 12 months or older need 2 doses of MMR at least 4 weeks apart.
• If yellow fever vaccine is needed, coordinate administration with a travel medicine clinic since both are live vaccines and must be given on the same day.
• Any person born after 1956 should have 2 doses of MMR at least 4 weeks apart if they have no evidence of immunity.
• Encourage parents to always inform you and your staff of any international travel plans.

Moving forward, remember this increased global activity and the presence of inadequately vaccinated individuals/communities keeps the United States at continued risk for measles outbreaks. The source of the next outbreak may only be one plane ride away.

Dr. Word is a pediatric infectious disease specialist and director of the Houston Travel Medicine Clinic. She said she had no relevant financial disclosures.

This article was updated 6/29/22.

References

1. Patel M et al. MMWR. 2019 Oct 11; 68(40):893-6.

2. Seither R et al. MMWR. 2022 Apr 22;71(16):561-8.

3. Gastañaduy PA et al. J Infect Dis. 2021 Sep 30;224(12 Suppl 2):S420-8. doi: 10.1093/infdis/jiaa793.

4. Centers for Disease Control and Prevention. Measles (Rubeola). http://www.CDC.gov/Measles.

The percentage of low-income pregnant mothers who received influenza and Tdap vaccinations fell sharply during the COVID-19 pandemic, especially in Black and Hispanic patients, a new study finds.

The percentage of patients who received the influenza vaccines at two Medicaid clinics in Houston dropped from 78% before the pandemic to 61% during it (adjusted odds ratio, 0.38; 95% CI, 0.26-0.53; P < .01), researchers reported at the annual clinical and scientific meeting of the American College of Obstetricians and Gynecologists. The percentage receiving the Tdap vaccine dipped from 85% to 76% (aOR, 0.56; 95% CI, 0.40-0.79; P < .01).

New York–Presbyterian/Weill Cornell Medical Center pediatrician Sallie Permar, MD, PhD, who’s familiar with the study findings, called them “alarming” and said in an interview that they should be “a call to action for providers.”

“Continuing the status quo in our routine preventative health care and clinic operations means that we are losing ground in reduction and elimination of vaccine-preventable diseases,” Dr. Permar said in an interview.

According to corresponding author Bani Ratan, MD, an ob.gyn. with the Baylor College of Medicine, Houston, there’s been little if any previous research into routine, non-COVID vaccination in pregnant women during the pandemic.

For the study, researchers retrospectively analyzed the records of 939 pregnant women who entered prenatal care before 20 weeks (462 from May–November 2019, and 477 from May–November 2020) and delivered at full term.

Among ethnic groups, non-Hispanic Blacks saw the largest decline in influenza vaccines. Among them, the percentage who got them fell from 64% (73/114) to 35% (35/101; aOR, 0.30; 95% CI, 0.17-0.52; P < .01). Only Hispanics had a statistically significant decline in Tdap vaccination (OR, 0.52, 95% CI, 0.34-0.80; P < .01, percentages not provided).

Another study presented at ACOG examined vaccination rates during the pandemic and found that Tdap vaccination rates dipped among pregnant women in a Philadelphia-area health care system.

Possible causes for the decline in routine vaccination include hesitancy linked to the COVID-19 vaccines and fewer office visits because of telemedicine, said Dr. Batan in an interview.

Dr. Permar blamed the role of vaccine misinformation during the pandemic and the mistrust caused by the exclusion of pregnant women from early vaccine trials. She added that “challenges in health care staffing and issues of health care provider burnout that worsened during the pandemic likely contributed to a fraying of the focus on preventive health maintenance simply due to bandwidth of health professionals.”

In a separate study presented at ACOG, researchers at the State University of New York, Syracuse, reported on a survey of 157 pregnant women of whom just 38.2% were vaccinated against COVID-19. Among the unvaccinated, who were more likely to have less education, 66% reported that lack of data about vaccination was their primary concern.

No funding or disclosures are reported by study authors. Dr. Permar reported consulting for Merck, Moderna, GlaxoSmithKline, Pfizer, Dynavax, and Hookipa on cytomegalovirus vaccine programs.

*This story was updated on 5/11/2022.

The percentage of low-income pregnant mothers who received influenza and Tdap vaccinations fell sharply during the COVID-19 pandemic, especially in Black and Hispanic patients, a new study finds.

The percentage of patients who received the influenza vaccines at two Medicaid clinics in Houston dropped from 78% before the pandemic to 61% during it (adjusted odds ratio, 0.38; 95% CI, 0.26-0.53; P < .01), researchers reported at the annual clinical and scientific meeting of the American College of Obstetricians and Gynecologists. The percentage receiving the Tdap vaccine dipped from 85% to 76% (aOR, 0.56; 95% CI, 0.40-0.79; P < .01).

New York–Presbyterian/Weill Cornell Medical Center pediatrician Sallie Permar, MD, PhD, who’s familiar with the study findings, called them “alarming” and said in an interview that they should be “a call to action for providers.”

“Continuing the status quo in our routine preventative health care and clinic operations means that we are losing ground in reduction and elimination of vaccine-preventable diseases,” Dr. Permar said in an interview.

According to corresponding author Bani Ratan, MD, an ob.gyn. with the Baylor College of Medicine, Houston, there’s been little if any previous research into routine, non-COVID vaccination in pregnant women during the pandemic.

For the study, researchers retrospectively analyzed the records of 939 pregnant women who entered prenatal care before 20 weeks (462 from May–November 2019, and 477 from May–November 2020) and delivered at full term.

Among ethnic groups, non-Hispanic Blacks saw the largest decline in influenza vaccines. Among them, the percentage who got them fell from 64% (73/114) to 35% (35/101; aOR, 0.30; 95% CI, 0.17-0.52; P < .01). Only Hispanics had a statistically significant decline in Tdap vaccination (OR, 0.52, 95% CI, 0.34-0.80; P < .01, percentages not provided).

Another study presented at ACOG examined vaccination rates during the pandemic and found that Tdap vaccination rates dipped among pregnant women in a Philadelphia-area health care system.

Possible causes for the decline in routine vaccination include hesitancy linked to the COVID-19 vaccines and fewer office visits because of telemedicine, said Dr. Batan in an interview.

Dr. Permar blamed the role of vaccine misinformation during the pandemic and the mistrust caused by the exclusion of pregnant women from early vaccine trials. She added that “challenges in health care staffing and issues of health care provider burnout that worsened during the pandemic likely contributed to a fraying of the focus on preventive health maintenance simply due to bandwidth of health professionals.”

In a separate study presented at ACOG, researchers at the State University of New York, Syracuse, reported on a survey of 157 pregnant women of whom just 38.2% were vaccinated against COVID-19. Among the unvaccinated, who were more likely to have less education, 66% reported that lack of data about vaccination was their primary concern.

No funding or disclosures are reported by study authors. Dr. Permar reported consulting for Merck, Moderna, GlaxoSmithKline, Pfizer, Dynavax, and Hookipa on cytomegalovirus vaccine programs.

*This story was updated on 5/11/2022.

The percentage of low-income pregnant mothers who received influenza and Tdap vaccinations fell sharply during the COVID-19 pandemic, especially in Black and Hispanic patients, a new study finds.

The percentage of patients who received the influenza vaccines at two Medicaid clinics in Houston dropped from 78% before the pandemic to 61% during it (adjusted odds ratio, 0.38; 95% CI, 0.26-0.53; P < .01), researchers reported at the annual clinical and scientific meeting of the American College of Obstetricians and Gynecologists. The percentage receiving the Tdap vaccine dipped from 85% to 76% (aOR, 0.56; 95% CI, 0.40-0.79; P < .01).

New York–Presbyterian/Weill Cornell Medical Center pediatrician Sallie Permar, MD, PhD, who’s familiar with the study findings, called them “alarming” and said in an interview that they should be “a call to action for providers.”

“Continuing the status quo in our routine preventative health care and clinic operations means that we are losing ground in reduction and elimination of vaccine-preventable diseases,” Dr. Permar said in an interview.

According to corresponding author Bani Ratan, MD, an ob.gyn. with the Baylor College of Medicine, Houston, there’s been little if any previous research into routine, non-COVID vaccination in pregnant women during the pandemic.

For the study, researchers retrospectively analyzed the records of 939 pregnant women who entered prenatal care before 20 weeks (462 from May–November 2019, and 477 from May–November 2020) and delivered at full term.

Among ethnic groups, non-Hispanic Blacks saw the largest decline in influenza vaccines. Among them, the percentage who got them fell from 64% (73/114) to 35% (35/101; aOR, 0.30; 95% CI, 0.17-0.52; P < .01). Only Hispanics had a statistically significant decline in Tdap vaccination (OR, 0.52, 95% CI, 0.34-0.80; P < .01, percentages not provided).

Another study presented at ACOG examined vaccination rates during the pandemic and found that Tdap vaccination rates dipped among pregnant women in a Philadelphia-area health care system.

Possible causes for the decline in routine vaccination include hesitancy linked to the COVID-19 vaccines and fewer office visits because of telemedicine, said Dr. Batan in an interview.

Dr. Permar blamed the role of vaccine misinformation during the pandemic and the mistrust caused by the exclusion of pregnant women from early vaccine trials. She added that “challenges in health care staffing and issues of health care provider burnout that worsened during the pandemic likely contributed to a fraying of the focus on preventive health maintenance simply due to bandwidth of health professionals.”

In a separate study presented at ACOG, researchers at the State University of New York, Syracuse, reported on a survey of 157 pregnant women of whom just 38.2% were vaccinated against COVID-19. Among the unvaccinated, who were more likely to have less education, 66% reported that lack of data about vaccination was their primary concern.

No funding or disclosures are reported by study authors. Dr. Permar reported consulting for Merck, Moderna, GlaxoSmithKline, Pfizer, Dynavax, and Hookipa on cytomegalovirus vaccine programs.

*This story was updated on 5/11/2022.

Having had a recent acute febrile illness was associated with an increased risk for ischemic stroke, whereas having received an influenza vaccination was associated with a reduced risk for stroke in a large new case-control study.

“While influenza vaccination is a cost-effective method to prevent influenza, it is also an effective way to reduce the burden of stroke,” said study author Christopher Schwarzbach, MD, of Ludwigshafen (Germany) Hospital.  

“Our results therefore encourage the wider use of influenza vaccination,” he concluded.

Dr. Schwarzbach presented these data from the INTERSTROKE study at the 2022 European Stroke Organisation Conference.

He explained that acute inflammatory disease is thought to increase the risk for cerebrovascular events, and the seasonality of influenza-like illness appears to be associated with the seasonality of cardiovascular and cerebrovascular events. Previous observational studies have also shown a link between influenza vaccination and a reduced risk for stroke.

The current INTERSTROKE study was a large international case-control study conducted between 2007 and 2015 that involved 13,447 cases (patients within 5 days of their first stroke) and a similar number of age- and gender-matched people from 32 countries across the world.

All cases and control subjects were systematically asked whether they had acute febrile illness in the previous 4 weeks and whether they had received an influenza vaccination within the previous year.

Conditional logistical regression was used to quantify the results, with adjustment for 13 different possible confounding factors, including hypertension, activity, smoking, cardiovascular risk factors, and socioeconomic factors.

Results showed that having had an acute febrile illness in the previous 4 weeks was more commonly reported in the patients with an acute ischemic stroke (8.7%) than in control patients (5.6%). After adjustment for confounding factors, this gives an adjusted risk ratio of 1.18, which was of borderline statistical significance (95% confidence limits, 1.01-1.39), Dr. Schwarzbach reported.

The association between recent febrile illness and acute ischemic stroke was stronger when compared with community control subjects (adjusted odds ratio, 2.0), but it was absent when compared with hospital control subjects.

The association was also only apparent in Australia, China, North America, and Western Europe; it was not seen in other parts of the world.

There was no association between acute febrile illness and acute cerebral hemorrhage.
 

Flu vaccine linked to halving of stroke risk

Having received a flu vaccine in the previous year was strongly associated with a lower risk for any type of stroke (aOR, 0.53), ischemic stroke (aOR, 0.57), and hemorrhagic stroke (aOR, 0.34).

Dr. Schwarzbach noted that these results were also consistent in an extended statistical model that included variables that might reflect a willingness to be vaccinated and when compared with both community and hospital-based control subjects.

The strength of the association between influenza vaccination and reduced risk for stroke was similar when compared with either community or hospital control subjects, and was only moderately stronger during than outside the influenza season.

The association was also seen in all regions of the world apart from Africa and South Asia, Dr. Schwarzbach reported, but he noted that vaccination rates in these two regions were extremely low.  

The researchers also found that the magnitude of the associations between flu vaccination and lower risk for stroke were stronger in individuals who had multiple annual vaccinations, with an odds ratio of 0.54 in those who had received a vaccine every year for the previous 5 years, and of 0.79 in those who had received one to four vaccinations in the previous 5 years.
 

Mechanism: Immune stimulation?

Discussing possible mechanisms behind these results, Dr. Schwarzbach noted that the finding that the association with influenza vaccination and reduced stroke risk was independent of seasonality was surprising. “We had expected the protective effect of vaccination to be bigger during the influenza season, but this wasn’t the case.”

He suggested that one explanation might be the inclusion of regions of the world where this seasonality doesn’t exist.

But he pointed out that the finding of a stronger association between flu vaccination and lower stroke risk in those who had received more vaccinations has given rise to another theory: that it is the stimulation of the immune system rather than the protection of infection against influenza that is the key factor.

In an interview with Dr. Schwarzbach, Guillaume Turk, MD, professor of neurology at GHU Paris, pointed out that causal inferences are always difficult in case-control studies and in clinical epidemiology in general.

“What makes you think that this association between influenza vaccination and decreased risk is causal rather than due to unmeasured confounders? For example, patients who received vaccination may have received more medical attention and may have been more aware of the risk factors for stroke,” he asked.  

Dr. Schwarzbach replied: “Yes, this is the issue of healthy user bias, which is always a problem in this type of research and is hard to address.”

“What we tried to do here is to adjust for variables that might influence the willingness of people to get vaccinated,” he added. “These were mainly socioeconomic factors. But, of course, this is something that we can’t rule out.”

Dr. Schwarzbach noted that, for more reliable information on this association, prospective studies are needed.
 

‘A plausible effect’

Discussing the study after the presentation, William Whiteley, BM, PhD, a clinical epidemiologist at the University of Edinburgh and a consultant neurologist in NHS Lothian, said vaccination was a potentially important way to reduce stroke.

“In this study, there was a plausible effect on reducing stroke incidence from vaccination against influenza, and also a plausible increase in the risk of stroke from having a recent febrile illness, which we have seen in other studies,” he commented.

Dr. Whiteley noted that this observation was particularly relevant now because of the COVID-19 pandemic.

“We’ve all been worried about the risk of heart attack and stroke after COVID, where we’ve seen quite early high risks, and we are also optimistic about the effect of vaccination on reducing those incidences. We’ve seen data from the U.K. that there may be around a 20% reduction in risk of stroke from vaccination. So, it’s all quite plausible, but at the moment it’s all based on observational evidence and we really need some randomized evidence,” he said.  

“Vaccination and infections have all sorts of odd confounders,” he added. “People who get vaccines tend to be more healthy than those who don’t get vaccines, so you can start to see quite implausible effects of vaccination on overall mortality, which probably aren’t real, and you probably can’t get rid of that totally with statistical methods.”

Alastair Webb, MD, University of Oxford (England), asked how reliable the current findings were, given that the occurrence of febrile illnesses and receipt of vaccines were all self-reported, and although there was an association for ischemic stroke and febrile illness, this seemed to go in the opposite direction for hemorrhagic stroke. He also noted that the 50% reduction in stroke risk with vaccination in this study seemed “quite a large magnitude of effect.”

Dr. Whiteley replied: “Yes, it is large, but it is promising.” He cited a previous meta-analysis of randomized studies that showed a roughly 25%-35% reduction in vascular events after flu vaccination, but noted that there was a lot of heterogeneity between studies.

“I’m not sure we’re going to see much more randomized evidence, but I think we can probably all agree that having a vaccine against flu or COVID is a good thing for all of us,” Dr. Whiteley concluded.

The INTERSTROKE study was funded by the Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Canadian Stroke Network, Health Research Board Ireland, Swedish Research Council, Swedish Heart and Lung Foundation, The Health & Medical Care Committee of the Regional Executive Board, Region Vastra Gotaland (Sweden), AstraZeneca, Boehringer Ingelheim, Pfizer, MSD, Chest, Heart and Stroke Scotland, and The Stroke Association, with support from The UK Stroke Research Network. The authors reported no relevant disclosures.

A version of this article first appeared on Medscape.com.

Having had a recent acute febrile illness was associated with an increased risk for ischemic stroke, whereas having received an influenza vaccination was associated with a reduced risk for stroke in a large new case-control study.

“While influenza vaccination is a cost-effective method to prevent influenza, it is also an effective way to reduce the burden of stroke,” said study author Christopher Schwarzbach, MD, of Ludwigshafen (Germany) Hospital.  

“Our results therefore encourage the wider use of influenza vaccination,” he concluded.

Dr. Schwarzbach presented these data from the INTERSTROKE study at the 2022 European Stroke Organisation Conference.

He explained that acute inflammatory disease is thought to increase the risk for cerebrovascular events, and the seasonality of influenza-like illness appears to be associated with the seasonality of cardiovascular and cerebrovascular events. Previous observational studies have also shown a link between influenza vaccination and a reduced risk for stroke.

The current INTERSTROKE study was a large international case-control study conducted between 2007 and 2015 that involved 13,447 cases (patients within 5 days of their first stroke) and a similar number of age- and gender-matched people from 32 countries across the world.

All cases and control subjects were systematically asked whether they had acute febrile illness in the previous 4 weeks and whether they had received an influenza vaccination within the previous year.

Conditional logistical regression was used to quantify the results, with adjustment for 13 different possible confounding factors, including hypertension, activity, smoking, cardiovascular risk factors, and socioeconomic factors.

Results showed that having had an acute febrile illness in the previous 4 weeks was more commonly reported in the patients with an acute ischemic stroke (8.7%) than in control patients (5.6%). After adjustment for confounding factors, this gives an adjusted risk ratio of 1.18, which was of borderline statistical significance (95% confidence limits, 1.01-1.39), Dr. Schwarzbach reported.

The association between recent febrile illness and acute ischemic stroke was stronger when compared with community control subjects (adjusted odds ratio, 2.0), but it was absent when compared with hospital control subjects.

The association was also only apparent in Australia, China, North America, and Western Europe; it was not seen in other parts of the world.

There was no association between acute febrile illness and acute cerebral hemorrhage.
 

Flu vaccine linked to halving of stroke risk

Having received a flu vaccine in the previous year was strongly associated with a lower risk for any type of stroke (aOR, 0.53), ischemic stroke (aOR, 0.57), and hemorrhagic stroke (aOR, 0.34).

Dr. Schwarzbach noted that these results were also consistent in an extended statistical model that included variables that might reflect a willingness to be vaccinated and when compared with both community and hospital-based control subjects.

The strength of the association between influenza vaccination and reduced risk for stroke was similar when compared with either community or hospital control subjects, and was only moderately stronger during than outside the influenza season.

The association was also seen in all regions of the world apart from Africa and South Asia, Dr. Schwarzbach reported, but he noted that vaccination rates in these two regions were extremely low.  

The researchers also found that the magnitude of the associations between flu vaccination and lower risk for stroke were stronger in individuals who had multiple annual vaccinations, with an odds ratio of 0.54 in those who had received a vaccine every year for the previous 5 years, and of 0.79 in those who had received one to four vaccinations in the previous 5 years.
 

Mechanism: Immune stimulation?

Discussing possible mechanisms behind these results, Dr. Schwarzbach noted that the finding that the association with influenza vaccination and reduced stroke risk was independent of seasonality was surprising. “We had expected the protective effect of vaccination to be bigger during the influenza season, but this wasn’t the case.”

He suggested that one explanation might be the inclusion of regions of the world where this seasonality doesn’t exist.

But he pointed out that the finding of a stronger association between flu vaccination and lower stroke risk in those who had received more vaccinations has given rise to another theory: that it is the stimulation of the immune system rather than the protection of infection against influenza that is the key factor.

In an interview with Dr. Schwarzbach, Guillaume Turk, MD, professor of neurology at GHU Paris, pointed out that causal inferences are always difficult in case-control studies and in clinical epidemiology in general.

“What makes you think that this association between influenza vaccination and decreased risk is causal rather than due to unmeasured confounders? For example, patients who received vaccination may have received more medical attention and may have been more aware of the risk factors for stroke,” he asked.  

Dr. Schwarzbach replied: “Yes, this is the issue of healthy user bias, which is always a problem in this type of research and is hard to address.”

“What we tried to do here is to adjust for variables that might influence the willingness of people to get vaccinated,” he added. “These were mainly socioeconomic factors. But, of course, this is something that we can’t rule out.”

Dr. Schwarzbach noted that, for more reliable information on this association, prospective studies are needed.
 

‘A plausible effect’

Discussing the study after the presentation, William Whiteley, BM, PhD, a clinical epidemiologist at the University of Edinburgh and a consultant neurologist in NHS Lothian, said vaccination was a potentially important way to reduce stroke.

“In this study, there was a plausible effect on reducing stroke incidence from vaccination against influenza, and also a plausible increase in the risk of stroke from having a recent febrile illness, which we have seen in other studies,” he commented.

Dr. Whiteley noted that this observation was particularly relevant now because of the COVID-19 pandemic.

“We’ve all been worried about the risk of heart attack and stroke after COVID, where we’ve seen quite early high risks, and we are also optimistic about the effect of vaccination on reducing those incidences. We’ve seen data from the U.K. that there may be around a 20% reduction in risk of stroke from vaccination. So, it’s all quite plausible, but at the moment it’s all based on observational evidence and we really need some randomized evidence,” he said.  

“Vaccination and infections have all sorts of odd confounders,” he added. “People who get vaccines tend to be more healthy than those who don’t get vaccines, so you can start to see quite implausible effects of vaccination on overall mortality, which probably aren’t real, and you probably can’t get rid of that totally with statistical methods.”

Alastair Webb, MD, University of Oxford (England), asked how reliable the current findings were, given that the occurrence of febrile illnesses and receipt of vaccines were all self-reported, and although there was an association for ischemic stroke and febrile illness, this seemed to go in the opposite direction for hemorrhagic stroke. He also noted that the 50% reduction in stroke risk with vaccination in this study seemed “quite a large magnitude of effect.”

Dr. Whiteley replied: “Yes, it is large, but it is promising.” He cited a previous meta-analysis of randomized studies that showed a roughly 25%-35% reduction in vascular events after flu vaccination, but noted that there was a lot of heterogeneity between studies.

“I’m not sure we’re going to see much more randomized evidence, but I think we can probably all agree that having a vaccine against flu or COVID is a good thing for all of us,” Dr. Whiteley concluded.

The INTERSTROKE study was funded by the Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Canadian Stroke Network, Health Research Board Ireland, Swedish Research Council, Swedish Heart and Lung Foundation, The Health & Medical Care Committee of the Regional Executive Board, Region Vastra Gotaland (Sweden), AstraZeneca, Boehringer Ingelheim, Pfizer, MSD, Chest, Heart and Stroke Scotland, and The Stroke Association, with support from The UK Stroke Research Network. The authors reported no relevant disclosures.

A version of this article first appeared on Medscape.com.

Having had a recent acute febrile illness was associated with an increased risk for ischemic stroke, whereas having received an influenza vaccination was associated with a reduced risk for stroke in a large new case-control study.

“While influenza vaccination is a cost-effective method to prevent influenza, it is also an effective way to reduce the burden of stroke,” said study author Christopher Schwarzbach, MD, of Ludwigshafen (Germany) Hospital.  

“Our results therefore encourage the wider use of influenza vaccination,” he concluded.

Dr. Schwarzbach presented these data from the INTERSTROKE study at the 2022 European Stroke Organisation Conference.

He explained that acute inflammatory disease is thought to increase the risk for cerebrovascular events, and the seasonality of influenza-like illness appears to be associated with the seasonality of cardiovascular and cerebrovascular events. Previous observational studies have also shown a link between influenza vaccination and a reduced risk for stroke.

The current INTERSTROKE study was a large international case-control study conducted between 2007 and 2015 that involved 13,447 cases (patients within 5 days of their first stroke) and a similar number of age- and gender-matched people from 32 countries across the world.

All cases and control subjects were systematically asked whether they had acute febrile illness in the previous 4 weeks and whether they had received an influenza vaccination within the previous year.

Conditional logistical regression was used to quantify the results, with adjustment for 13 different possible confounding factors, including hypertension, activity, smoking, cardiovascular risk factors, and socioeconomic factors.

Results showed that having had an acute febrile illness in the previous 4 weeks was more commonly reported in the patients with an acute ischemic stroke (8.7%) than in control patients (5.6%). After adjustment for confounding factors, this gives an adjusted risk ratio of 1.18, which was of borderline statistical significance (95% confidence limits, 1.01-1.39), Dr. Schwarzbach reported.

The association between recent febrile illness and acute ischemic stroke was stronger when compared with community control subjects (adjusted odds ratio, 2.0), but it was absent when compared with hospital control subjects.

The association was also only apparent in Australia, China, North America, and Western Europe; it was not seen in other parts of the world.

There was no association between acute febrile illness and acute cerebral hemorrhage.
 

Flu vaccine linked to halving of stroke risk

Having received a flu vaccine in the previous year was strongly associated with a lower risk for any type of stroke (aOR, 0.53), ischemic stroke (aOR, 0.57), and hemorrhagic stroke (aOR, 0.34).

Dr. Schwarzbach noted that these results were also consistent in an extended statistical model that included variables that might reflect a willingness to be vaccinated and when compared with both community and hospital-based control subjects.

The strength of the association between influenza vaccination and reduced risk for stroke was similar when compared with either community or hospital control subjects, and was only moderately stronger during than outside the influenza season.

The association was also seen in all regions of the world apart from Africa and South Asia, Dr. Schwarzbach reported, but he noted that vaccination rates in these two regions were extremely low.  

The researchers also found that the magnitude of the associations between flu vaccination and lower risk for stroke were stronger in individuals who had multiple annual vaccinations, with an odds ratio of 0.54 in those who had received a vaccine every year for the previous 5 years, and of 0.79 in those who had received one to four vaccinations in the previous 5 years.
 

Mechanism: Immune stimulation?

Discussing possible mechanisms behind these results, Dr. Schwarzbach noted that the finding that the association with influenza vaccination and reduced stroke risk was independent of seasonality was surprising. “We had expected the protective effect of vaccination to be bigger during the influenza season, but this wasn’t the case.”

He suggested that one explanation might be the inclusion of regions of the world where this seasonality doesn’t exist.

But he pointed out that the finding of a stronger association between flu vaccination and lower stroke risk in those who had received more vaccinations has given rise to another theory: that it is the stimulation of the immune system rather than the protection of infection against influenza that is the key factor.

In an interview with Dr. Schwarzbach, Guillaume Turk, MD, professor of neurology at GHU Paris, pointed out that causal inferences are always difficult in case-control studies and in clinical epidemiology in general.

“What makes you think that this association between influenza vaccination and decreased risk is causal rather than due to unmeasured confounders? For example, patients who received vaccination may have received more medical attention and may have been more aware of the risk factors for stroke,” he asked.  

Dr. Schwarzbach replied: “Yes, this is the issue of healthy user bias, which is always a problem in this type of research and is hard to address.”

“What we tried to do here is to adjust for variables that might influence the willingness of people to get vaccinated,” he added. “These were mainly socioeconomic factors. But, of course, this is something that we can’t rule out.”

Dr. Schwarzbach noted that, for more reliable information on this association, prospective studies are needed.
 

‘A plausible effect’

Discussing the study after the presentation, William Whiteley, BM, PhD, a clinical epidemiologist at the University of Edinburgh and a consultant neurologist in NHS Lothian, said vaccination was a potentially important way to reduce stroke.

“In this study, there was a plausible effect on reducing stroke incidence from vaccination against influenza, and also a plausible increase in the risk of stroke from having a recent febrile illness, which we have seen in other studies,” he commented.

Dr. Whiteley noted that this observation was particularly relevant now because of the COVID-19 pandemic.

“We’ve all been worried about the risk of heart attack and stroke after COVID, where we’ve seen quite early high risks, and we are also optimistic about the effect of vaccination on reducing those incidences. We’ve seen data from the U.K. that there may be around a 20% reduction in risk of stroke from vaccination. So, it’s all quite plausible, but at the moment it’s all based on observational evidence and we really need some randomized evidence,” he said.  

“Vaccination and infections have all sorts of odd confounders,” he added. “People who get vaccines tend to be more healthy than those who don’t get vaccines, so you can start to see quite implausible effects of vaccination on overall mortality, which probably aren’t real, and you probably can’t get rid of that totally with statistical methods.”

Alastair Webb, MD, University of Oxford (England), asked how reliable the current findings were, given that the occurrence of febrile illnesses and receipt of vaccines were all self-reported, and although there was an association for ischemic stroke and febrile illness, this seemed to go in the opposite direction for hemorrhagic stroke. He also noted that the 50% reduction in stroke risk with vaccination in this study seemed “quite a large magnitude of effect.”

Dr. Whiteley replied: “Yes, it is large, but it is promising.” He cited a previous meta-analysis of randomized studies that showed a roughly 25%-35% reduction in vascular events after flu vaccination, but noted that there was a lot of heterogeneity between studies.

“I’m not sure we’re going to see much more randomized evidence, but I think we can probably all agree that having a vaccine against flu or COVID is a good thing for all of us,” Dr. Whiteley concluded.

The INTERSTROKE study was funded by the Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Canadian Stroke Network, Health Research Board Ireland, Swedish Research Council, Swedish Heart and Lung Foundation, The Health & Medical Care Committee of the Regional Executive Board, Region Vastra Gotaland (Sweden), AstraZeneca, Boehringer Ingelheim, Pfizer, MSD, Chest, Heart and Stroke Scotland, and The Stroke Association, with support from The UK Stroke Research Network. The authors reported no relevant disclosures.

A version of this article first appeared on Medscape.com.

In this column I have previously discussed the microbiome and its importance to health, especially as it relates to infections in children. Given the appreciated connection between microbiome and immunity, my group in Rochester, N.Y., recently undertook a study of the effect of antibiotic usage on the immune response to routine early childhood vaccines. In mouse models, it was previously shown that antibiotic exposure induced a reduction in the abundance and diversity of gut microbiota that in turn negatively affected the generation and maintenance of vaccine-induced immunity.^1,2 A study from Stanford University was the first experimental human trial of antibiotic effects on vaccine responses. Adult volunteers were given an antibiotic or not before seasonal influenza vaccination and the researchers identified specific bacteria in the gut that were reduced by the antibiotics given. Those normal bacteria in the gut microbiome were shown to provide positive immunity signals to the systemic immune system that potentiated vaccine responses.³

My group conducted the first-ever study in children to explore whether an association existed between antibiotic use and vaccine-induced antibody levels. In the May issue of Pediatrics we report results from 560 children studied.⁴ From these children, 11,888 serum antibody levels to vaccine antigens were measured. Vaccine-induced antibody levels were determined at various time points after primary vaccination at child age 2, 4, and 6 months and boosters at age 12-18 months for 10 antigens included in four vaccines: DTaP, Hib, IPV, and PCV. The antibody levels to vaccine components were measured to DTaP (diphtheria toxoid, pertussis toxoid, tetanus toxoid, pertactin, and filamentous hemagglutinin), Hib conjugate (polyribosylribitol phosphate), IPV (polio 2), and PCV (serotypes 6B, 14, and 23F). A total of 342 children with 1,678 antibiotic courses prescribed were compared with 218 children with no antibiotic exposures. The predominant antibiotics prescribed were amoxicillin, cefdinir, amoxicillin/clavulanate, and ceftriaxone, since most treatments were for acute otitis media.

Of possible high clinical relevance, we found that from 9 to 24 months of age, children with antibiotic exposure had a higher frequency of vaccine-induced antibody levels below protection compared with children with no antibiotic use, placing them at risk of contracting a vaccine-preventable infection for DTaP antigens DT, TT, and PT and for PCV serotype 14.

For time points where antibody levels were determined within 30 days of completion of a course of antibiotics (recent antibiotic use), individual antibiotics were analyzed for effect on antibody levels below protective levels. Across all vaccine antigens measured, we found that all antibiotics had a negative effect on antibody levels and percentage of children achieving the protective antibody level threshold. Amoxicillin use had a lower association with lower antibody levels than the broader spectrum antibiotics, amoxicillin clavulanate (Augmentin), cefdinir, and ceftriaxone. For children receiving amoxicillin/clavulanate prescriptions, it was possible to compare the effect of shorter versus longer courses and we found that a 5-day course was associated with subprotective antibody levels similar to 10 days of amoxicillin, whereas 10-day amoxicillin/clavulanate was associated with higher frequency of children having subprotective antibody levels (Figure).

We examined whether accumulation of antibiotic courses in the first year of life had an association with subsequent vaccine-induced antibody levels and found that each antibiotic prescription was associated with a reduction in the median antibody level. For DTaP, each prescription was associated with 5.8% drop in antibody level to the vaccine components. For Hib the drop was 6.8%, IPV was 11.3%, and PCV was 10.4% – all statistically significant. To determine if booster vaccination influenced this association, a second analysis was performed using antibiotic prescriptions up to 15 months of age. We found each antibiotic prescription was associated with a reduction in median vaccine-induced antibody levels for DTaP by 18%, Hib by 21%, IPV by 19%, and PCV by 12% – all statistically significant.

Our study is the first in young children during the early age window where vaccine-induced immunity is established. Antibiotic use was associated with increased frequency of subprotective antibody levels for several vaccines used in children up to 2 years of age. The lower antibody levels could leave children vulnerable to vaccine preventable diseases. Perhaps outbreaks of vaccine-preventable diseases, such as pertussis, may be a consequence of multiple courses of antibiotics suppressing vaccine-induced immunity.

A goal of this study was to explore potential acute and long-term effects of antibiotic exposure on vaccine-induced antibody levels. Accumulated antibiotic courses up to booster immunization was associated with decreased vaccine antibody levels both before and after booster, suggesting that booster immunization was not sufficient to change the negative association with antibiotic exposure. The results were similar for all vaccines tested, suggesting that the specific vaccine formulation was not a factor.

The study has several limitations. The antibiotic prescription data and measurements of vaccine-induced antibody levels were recorded and measured prospectively; however, our analysis was done retrospectively. The group of study children was derived from my private practice in Rochester, N.Y., and may not be broadly representative of all children. The number of vaccine antibody measurements was limited by serum availability at some sampling time points in some children; and sometimes, the serum samples were collected far apart, which weakened our ability to perform longitudinal analyses. We did not collect stool samples from the children so we could not directly study the effect of antibiotic courses on the gut microbiome.

Our study adds new reasons to be cautious about overprescribing antibiotics on an individual child basis because an adverse effect extends to reduction in vaccine responses. This should be explained to parents requesting unnecessary antibiotics for colds and coughs. When antibiotics are necessary, the judicious choice of a narrow-spectrum antibiotic or a shorter duration of a broader spectrum antibiotic may reduce adverse effects on vaccine-induced immunity.

References

1. Valdez Y et al. Influence of the microbiota on vaccine effectiveness. Trends Immunol. 2014;35(11):526-37.

2. Lynn MA et al. Early-life antibiotic-driven dysbiosis leads to dysregulated vaccine immune responses in mice. Cell Host Microbe. 2018;23(5):653-60.e5.

3. Hagan T et al. Antibiotics-driven gut microbiome perturbation alters immunity to vaccines in humans. Cell. 2019;178(6):1313-28.e13.

4. Chapman T et al. Antibiotic use and vaccine antibody levels. Pediatrics. 2022;149(5);1-17. doi: 10.1542/peds.2021-052061.

In this column I have previously discussed the microbiome and its importance to health, especially as it relates to infections in children. Given the appreciated connection between microbiome and immunity, my group in Rochester, N.Y., recently undertook a study of the effect of antibiotic usage on the immune response to routine early childhood vaccines. In mouse models, it was previously shown that antibiotic exposure induced a reduction in the abundance and diversity of gut microbiota that in turn negatively affected the generation and maintenance of vaccine-induced immunity.^1,2 A study from Stanford University was the first experimental human trial of antibiotic effects on vaccine responses. Adult volunteers were given an antibiotic or not before seasonal influenza vaccination and the researchers identified specific bacteria in the gut that were reduced by the antibiotics given. Those normal bacteria in the gut microbiome were shown to provide positive immunity signals to the systemic immune system that potentiated vaccine responses.³

My group conducted the first-ever study in children to explore whether an association existed between antibiotic use and vaccine-induced antibody levels. In the May issue of Pediatrics we report results from 560 children studied.⁴ From these children, 11,888 serum antibody levels to vaccine antigens were measured. Vaccine-induced antibody levels were determined at various time points after primary vaccination at child age 2, 4, and 6 months and boosters at age 12-18 months for 10 antigens included in four vaccines: DTaP, Hib, IPV, and PCV. The antibody levels to vaccine components were measured to DTaP (diphtheria toxoid, pertussis toxoid, tetanus toxoid, pertactin, and filamentous hemagglutinin), Hib conjugate (polyribosylribitol phosphate), IPV (polio 2), and PCV (serotypes 6B, 14, and 23F). A total of 342 children with 1,678 antibiotic courses prescribed were compared with 218 children with no antibiotic exposures. The predominant antibiotics prescribed were amoxicillin, cefdinir, amoxicillin/clavulanate, and ceftriaxone, since most treatments were for acute otitis media.

Of possible high clinical relevance, we found that from 9 to 24 months of age, children with antibiotic exposure had a higher frequency of vaccine-induced antibody levels below protection compared with children with no antibiotic use, placing them at risk of contracting a vaccine-preventable infection for DTaP antigens DT, TT, and PT and for PCV serotype 14.

For time points where antibody levels were determined within 30 days of completion of a course of antibiotics (recent antibiotic use), individual antibiotics were analyzed for effect on antibody levels below protective levels. Across all vaccine antigens measured, we found that all antibiotics had a negative effect on antibody levels and percentage of children achieving the protective antibody level threshold. Amoxicillin use had a lower association with lower antibody levels than the broader spectrum antibiotics, amoxicillin clavulanate (Augmentin), cefdinir, and ceftriaxone. For children receiving amoxicillin/clavulanate prescriptions, it was possible to compare the effect of shorter versus longer courses and we found that a 5-day course was associated with subprotective antibody levels similar to 10 days of amoxicillin, whereas 10-day amoxicillin/clavulanate was associated with higher frequency of children having subprotective antibody levels (Figure).

We examined whether accumulation of antibiotic courses in the first year of life had an association with subsequent vaccine-induced antibody levels and found that each antibiotic prescription was associated with a reduction in the median antibody level. For DTaP, each prescription was associated with 5.8% drop in antibody level to the vaccine components. For Hib the drop was 6.8%, IPV was 11.3%, and PCV was 10.4% – all statistically significant. To determine if booster vaccination influenced this association, a second analysis was performed using antibiotic prescriptions up to 15 months of age. We found each antibiotic prescription was associated with a reduction in median vaccine-induced antibody levels for DTaP by 18%, Hib by 21%, IPV by 19%, and PCV by 12% – all statistically significant.

Our study is the first in young children during the early age window where vaccine-induced immunity is established. Antibiotic use was associated with increased frequency of subprotective antibody levels for several vaccines used in children up to 2 years of age. The lower antibody levels could leave children vulnerable to vaccine preventable diseases. Perhaps outbreaks of vaccine-preventable diseases, such as pertussis, may be a consequence of multiple courses of antibiotics suppressing vaccine-induced immunity.

A goal of this study was to explore potential acute and long-term effects of antibiotic exposure on vaccine-induced antibody levels. Accumulated antibiotic courses up to booster immunization was associated with decreased vaccine antibody levels both before and after booster, suggesting that booster immunization was not sufficient to change the negative association with antibiotic exposure. The results were similar for all vaccines tested, suggesting that the specific vaccine formulation was not a factor.

The study has several limitations. The antibiotic prescription data and measurements of vaccine-induced antibody levels were recorded and measured prospectively; however, our analysis was done retrospectively. The group of study children was derived from my private practice in Rochester, N.Y., and may not be broadly representative of all children. The number of vaccine antibody measurements was limited by serum availability at some sampling time points in some children; and sometimes, the serum samples were collected far apart, which weakened our ability to perform longitudinal analyses. We did not collect stool samples from the children so we could not directly study the effect of antibiotic courses on the gut microbiome.

Our study adds new reasons to be cautious about overprescribing antibiotics on an individual child basis because an adverse effect extends to reduction in vaccine responses. This should be explained to parents requesting unnecessary antibiotics for colds and coughs. When antibiotics are necessary, the judicious choice of a narrow-spectrum antibiotic or a shorter duration of a broader spectrum antibiotic may reduce adverse effects on vaccine-induced immunity.

References

1. Valdez Y et al. Influence of the microbiota on vaccine effectiveness. Trends Immunol. 2014;35(11):526-37.

2. Lynn MA et al. Early-life antibiotic-driven dysbiosis leads to dysregulated vaccine immune responses in mice. Cell Host Microbe. 2018;23(5):653-60.e5.

3. Hagan T et al. Antibiotics-driven gut microbiome perturbation alters immunity to vaccines in humans. Cell. 2019;178(6):1313-28.e13.

4. Chapman T et al. Antibiotic use and vaccine antibody levels. Pediatrics. 2022;149(5);1-17. doi: 10.1542/peds.2021-052061.

In this column I have previously discussed the microbiome and its importance to health, especially as it relates to infections in children. Given the appreciated connection between microbiome and immunity, my group in Rochester, N.Y., recently undertook a study of the effect of antibiotic usage on the immune response to routine early childhood vaccines. In mouse models, it was previously shown that antibiotic exposure induced a reduction in the abundance and diversity of gut microbiota that in turn negatively affected the generation and maintenance of vaccine-induced immunity.^1,2 A study from Stanford University was the first experimental human trial of antibiotic effects on vaccine responses. Adult volunteers were given an antibiotic or not before seasonal influenza vaccination and the researchers identified specific bacteria in the gut that were reduced by the antibiotics given. Those normal bacteria in the gut microbiome were shown to provide positive immunity signals to the systemic immune system that potentiated vaccine responses.³

My group conducted the first-ever study in children to explore whether an association existed between antibiotic use and vaccine-induced antibody levels. In the May issue of Pediatrics we report results from 560 children studied.⁴ From these children, 11,888 serum antibody levels to vaccine antigens were measured. Vaccine-induced antibody levels were determined at various time points after primary vaccination at child age 2, 4, and 6 months and boosters at age 12-18 months for 10 antigens included in four vaccines: DTaP, Hib, IPV, and PCV. The antibody levels to vaccine components were measured to DTaP (diphtheria toxoid, pertussis toxoid, tetanus toxoid, pertactin, and filamentous hemagglutinin), Hib conjugate (polyribosylribitol phosphate), IPV (polio 2), and PCV (serotypes 6B, 14, and 23F). A total of 342 children with 1,678 antibiotic courses prescribed were compared with 218 children with no antibiotic exposures. The predominant antibiotics prescribed were amoxicillin, cefdinir, amoxicillin/clavulanate, and ceftriaxone, since most treatments were for acute otitis media.

Of possible high clinical relevance, we found that from 9 to 24 months of age, children with antibiotic exposure had a higher frequency of vaccine-induced antibody levels below protection compared with children with no antibiotic use, placing them at risk of contracting a vaccine-preventable infection for DTaP antigens DT, TT, and PT and for PCV serotype 14.

For time points where antibody levels were determined within 30 days of completion of a course of antibiotics (recent antibiotic use), individual antibiotics were analyzed for effect on antibody levels below protective levels. Across all vaccine antigens measured, we found that all antibiotics had a negative effect on antibody levels and percentage of children achieving the protective antibody level threshold. Amoxicillin use had a lower association with lower antibody levels than the broader spectrum antibiotics, amoxicillin clavulanate (Augmentin), cefdinir, and ceftriaxone. For children receiving amoxicillin/clavulanate prescriptions, it was possible to compare the effect of shorter versus longer courses and we found that a 5-day course was associated with subprotective antibody levels similar to 10 days of amoxicillin, whereas 10-day amoxicillin/clavulanate was associated with higher frequency of children having subprotective antibody levels (Figure).

We examined whether accumulation of antibiotic courses in the first year of life had an association with subsequent vaccine-induced antibody levels and found that each antibiotic prescription was associated with a reduction in the median antibody level. For DTaP, each prescription was associated with 5.8% drop in antibody level to the vaccine components. For Hib the drop was 6.8%, IPV was 11.3%, and PCV was 10.4% – all statistically significant. To determine if booster vaccination influenced this association, a second analysis was performed using antibiotic prescriptions up to 15 months of age. We found each antibiotic prescription was associated with a reduction in median vaccine-induced antibody levels for DTaP by 18%, Hib by 21%, IPV by 19%, and PCV by 12% – all statistically significant.

Our study is the first in young children during the early age window where vaccine-induced immunity is established. Antibiotic use was associated with increased frequency of subprotective antibody levels for several vaccines used in children up to 2 years of age. The lower antibody levels could leave children vulnerable to vaccine preventable diseases. Perhaps outbreaks of vaccine-preventable diseases, such as pertussis, may be a consequence of multiple courses of antibiotics suppressing vaccine-induced immunity.

A goal of this study was to explore potential acute and long-term effects of antibiotic exposure on vaccine-induced antibody levels. Accumulated antibiotic courses up to booster immunization was associated with decreased vaccine antibody levels both before and after booster, suggesting that booster immunization was not sufficient to change the negative association with antibiotic exposure. The results were similar for all vaccines tested, suggesting that the specific vaccine formulation was not a factor.

The study has several limitations. The antibiotic prescription data and measurements of vaccine-induced antibody levels were recorded and measured prospectively; however, our analysis was done retrospectively. The group of study children was derived from my private practice in Rochester, N.Y., and may not be broadly representative of all children. The number of vaccine antibody measurements was limited by serum availability at some sampling time points in some children; and sometimes, the serum samples were collected far apart, which weakened our ability to perform longitudinal analyses. We did not collect stool samples from the children so we could not directly study the effect of antibiotic courses on the gut microbiome.

Our study adds new reasons to be cautious about overprescribing antibiotics on an individual child basis because an adverse effect extends to reduction in vaccine responses. This should be explained to parents requesting unnecessary antibiotics for colds and coughs. When antibiotics are necessary, the judicious choice of a narrow-spectrum antibiotic or a shorter duration of a broader spectrum antibiotic may reduce adverse effects on vaccine-induced immunity.

References

1. Valdez Y et al. Influence of the microbiota on vaccine effectiveness. Trends Immunol. 2014;35(11):526-37.

2. Lynn MA et al. Early-life antibiotic-driven dysbiosis leads to dysregulated vaccine immune responses in mice. Cell Host Microbe. 2018;23(5):653-60.e5.

3. Hagan T et al. Antibiotics-driven gut microbiome perturbation alters immunity to vaccines in humans. Cell. 2019;178(6):1313-28.e13.

4. Chapman T et al. Antibiotic use and vaccine antibody levels. Pediatrics. 2022;149(5);1-17. doi: 10.1542/peds.2021-052061.

Vaccination rates among kindergartners in the United States dipped below the Healthy People 2030 target of 95% in 2020-2021, according to the latest figures from the Centers for Disease Control and Prevention.

Data from 47 states and the District of Columbia, reported in the Morbidity and Mortality Weekly Report, showed the rates dipped by about 1 percentage point, compared with the previous school year for state-required vaccines. Coverage nationally was 93.9% for two doses of the MMR vaccine, 93.6% for the required number of doses of DTaP, and 93.6% for the state-required doses of varicella vaccine.

“This might not sound like much,” Georgina Peacock, MD, MPH, acting director of CDC’s immunization services division said in a press briefing. “But it amounts to at least 35,000 more children across the United States that entered kindergarten without documentation of complete vaccination against common diseases like measles, whooping cough, and chickenpox.”

The report authors, led by Ranee Seither, MPH, with the immunization services division of the CDC’s National Center for Immunization and Respiratory Diseases, said the COVID-19 pandemic played a large part in the dip as children missed doctors’ appointments and states relaxed requirements with remote instruction.

States reported reluctance by parents to schedule well-child appointments and reduced access to office visits as well as longer grace periods or provisional enrollment. There was also less submission of documentation by parents, less time for school nurses to follow-up with students to document vaccines, fewer staff members to conduct kindergarten vaccination coverage assessment, lower response rates from schools, and both extended and compressed kindergarten vaccination coverage data collection schedules.

“There’s a greater proportion of parents who are questioning routine vaccines,” Jason V. Terk, MD, a Texas pediatrician and a spokesman for the American Academy of Pediatrics, told the New York Times. He said misinformation “fed the fire of distrust and skepticism that is really sort of the new pandemic of hesitancy for routine vaccines.”

The authors of the CDC report wrote: “As schools continue to return to in-person learning, enforcement of vaccination policies and follow-up with undervaccinated students are important to improve vaccination coverage.”

They urged schools and immunization programs to reach out to first-time students, including kindergartners and first-graders, and follow up with undervaccinated students.

The rate of people having an exemption from at least one vaccine remained low at 2.2% and the percentage of children with exemptions decreased in 37 states. However, an additional 3.9% who did not have a vaccine exemption were not up to date for MMR, according to the report.

Mississippi and New York had the smallest percentage of exemptions (0.1%) and Idaho had the most (8.2%). In the 2019-2020 school year, 2.5% reported an exemption from at least one vaccine. Nationally, 0.2% of kindergartners had a medical exemption and 1.9% had a nonmedical exemption.

Vaccination rates also differed among states. The New York Times noted that Maryland had a 10% drop in MMR vaccine coverage, while Wisconsin, Georgia, Wyoming, and Kentucky had declines of about 5%.

Among states reporting the measures in 2020-2021, the proportion of kindergartners attending school with no documentation of required vaccinations or exemptions ranged from 0.1% (Pennsylvania and Virginia) to 8.3% (Maryland). The state with the lowest proportion of kindergarteners out of compliance was Florida (0.2%) and Indiana had the highest out-of-compliance rate at 16.6%.

Comparing states’ performance is difficult, the authors noted, because they vary as to which vaccine and number of doses they require and by what date and what documentation they require. They also vary by data collection methods; exemptions allowed; grace period rules and provisional enrollment.

The authors, Dr. Peacock, and Dr. Terk reported no relevant financial disclosures.

Vaccination rates among kindergartners in the United States dipped below the Healthy People 2030 target of 95% in 2020-2021, according to the latest figures from the Centers for Disease Control and Prevention.

Data from 47 states and the District of Columbia, reported in the Morbidity and Mortality Weekly Report, showed the rates dipped by about 1 percentage point, compared with the previous school year for state-required vaccines. Coverage nationally was 93.9% for two doses of the MMR vaccine, 93.6% for the required number of doses of DTaP, and 93.6% for the state-required doses of varicella vaccine.

“This might not sound like much,” Georgina Peacock, MD, MPH, acting director of CDC’s immunization services division said in a press briefing. “But it amounts to at least 35,000 more children across the United States that entered kindergarten without documentation of complete vaccination against common diseases like measles, whooping cough, and chickenpox.”

The report authors, led by Ranee Seither, MPH, with the immunization services division of the CDC’s National Center for Immunization and Respiratory Diseases, said the COVID-19 pandemic played a large part in the dip as children missed doctors’ appointments and states relaxed requirements with remote instruction.

States reported reluctance by parents to schedule well-child appointments and reduced access to office visits as well as longer grace periods or provisional enrollment. There was also less submission of documentation by parents, less time for school nurses to follow-up with students to document vaccines, fewer staff members to conduct kindergarten vaccination coverage assessment, lower response rates from schools, and both extended and compressed kindergarten vaccination coverage data collection schedules.

“There’s a greater proportion of parents who are questioning routine vaccines,” Jason V. Terk, MD, a Texas pediatrician and a spokesman for the American Academy of Pediatrics, told the New York Times. He said misinformation “fed the fire of distrust and skepticism that is really sort of the new pandemic of hesitancy for routine vaccines.”

The authors of the CDC report wrote: “As schools continue to return to in-person learning, enforcement of vaccination policies and follow-up with undervaccinated students are important to improve vaccination coverage.”

They urged schools and immunization programs to reach out to first-time students, including kindergartners and first-graders, and follow up with undervaccinated students.

The rate of people having an exemption from at least one vaccine remained low at 2.2% and the percentage of children with exemptions decreased in 37 states. However, an additional 3.9% who did not have a vaccine exemption were not up to date for MMR, according to the report.

Mississippi and New York had the smallest percentage of exemptions (0.1%) and Idaho had the most (8.2%). In the 2019-2020 school year, 2.5% reported an exemption from at least one vaccine. Nationally, 0.2% of kindergartners had a medical exemption and 1.9% had a nonmedical exemption.

Vaccination rates also differed among states. The New York Times noted that Maryland had a 10% drop in MMR vaccine coverage, while Wisconsin, Georgia, Wyoming, and Kentucky had declines of about 5%.

Among states reporting the measures in 2020-2021, the proportion of kindergartners attending school with no documentation of required vaccinations or exemptions ranged from 0.1% (Pennsylvania and Virginia) to 8.3% (Maryland). The state with the lowest proportion of kindergarteners out of compliance was Florida (0.2%) and Indiana had the highest out-of-compliance rate at 16.6%.

Comparing states’ performance is difficult, the authors noted, because they vary as to which vaccine and number of doses they require and by what date and what documentation they require. They also vary by data collection methods; exemptions allowed; grace period rules and provisional enrollment.

The authors, Dr. Peacock, and Dr. Terk reported no relevant financial disclosures.

Vaccination rates among kindergartners in the United States dipped below the Healthy People 2030 target of 95% in 2020-2021, according to the latest figures from the Centers for Disease Control and Prevention.

Data from 47 states and the District of Columbia, reported in the Morbidity and Mortality Weekly Report, showed the rates dipped by about 1 percentage point, compared with the previous school year for state-required vaccines. Coverage nationally was 93.9% for two doses of the MMR vaccine, 93.6% for the required number of doses of DTaP, and 93.6% for the state-required doses of varicella vaccine.

“This might not sound like much,” Georgina Peacock, MD, MPH, acting director of CDC’s immunization services division said in a press briefing. “But it amounts to at least 35,000 more children across the United States that entered kindergarten without documentation of complete vaccination against common diseases like measles, whooping cough, and chickenpox.”

The report authors, led by Ranee Seither, MPH, with the immunization services division of the CDC’s National Center for Immunization and Respiratory Diseases, said the COVID-19 pandemic played a large part in the dip as children missed doctors’ appointments and states relaxed requirements with remote instruction.

States reported reluctance by parents to schedule well-child appointments and reduced access to office visits as well as longer grace periods or provisional enrollment. There was also less submission of documentation by parents, less time for school nurses to follow-up with students to document vaccines, fewer staff members to conduct kindergarten vaccination coverage assessment, lower response rates from schools, and both extended and compressed kindergarten vaccination coverage data collection schedules.

“There’s a greater proportion of parents who are questioning routine vaccines,” Jason V. Terk, MD, a Texas pediatrician and a spokesman for the American Academy of Pediatrics, told the New York Times. He said misinformation “fed the fire of distrust and skepticism that is really sort of the new pandemic of hesitancy for routine vaccines.”

The authors of the CDC report wrote: “As schools continue to return to in-person learning, enforcement of vaccination policies and follow-up with undervaccinated students are important to improve vaccination coverage.”

They urged schools and immunization programs to reach out to first-time students, including kindergartners and first-graders, and follow up with undervaccinated students.

The rate of people having an exemption from at least one vaccine remained low at 2.2% and the percentage of children with exemptions decreased in 37 states. However, an additional 3.9% who did not have a vaccine exemption were not up to date for MMR, according to the report.

Mississippi and New York had the smallest percentage of exemptions (0.1%) and Idaho had the most (8.2%). In the 2019-2020 school year, 2.5% reported an exemption from at least one vaccine. Nationally, 0.2% of kindergartners had a medical exemption and 1.9% had a nonmedical exemption.

Vaccination rates also differed among states. The New York Times noted that Maryland had a 10% drop in MMR vaccine coverage, while Wisconsin, Georgia, Wyoming, and Kentucky had declines of about 5%.

Among states reporting the measures in 2020-2021, the proportion of kindergartners attending school with no documentation of required vaccinations or exemptions ranged from 0.1% (Pennsylvania and Virginia) to 8.3% (Maryland). The state with the lowest proportion of kindergarteners out of compliance was Florida (0.2%) and Indiana had the highest out-of-compliance rate at 16.6%.

Comparing states’ performance is difficult, the authors noted, because they vary as to which vaccine and number of doses they require and by what date and what documentation they require. They also vary by data collection methods; exemptions allowed; grace period rules and provisional enrollment.

The authors, Dr. Peacock, and Dr. Terk reported no relevant financial disclosures.

An overall ninefold increase in COVID-19 antibody levels can be seen with a longer interval between first and second doses of the Pfizer/BioNTech (BNT162b2) vaccine in people without prior infection, according to data from the U.K. government’s SIREN (SARS-CoV-2 Immunity and Reinfection Evaluation) study.

This interval-dependent antibody level varied by age, with those aged 45-54 years showing an 11-fold increase with a longer dosing interval (greater than 10 weeks vs. 2-4 weeks). People younger than age 25 years showed a 13-fold increase with the longer interval, but participant numbers were low in this sub-group.

Overall antibody levels in infection-naive participants were 1,268.72 Binding Antibody Units (BAU)/mL (1,043.25-1,542.91) in those with a 2-4–week interval, compared with 11,479.73 BAU/mL (10,742.78-12,267.24) (P < .0001), in those with at least a 10-week interval between doses.

The work is the latest analysis from SIREN, which measured antibody levels in the blood from nearly 6,000 health care workers from across the United Kingdom. Study lead Ashley Otter, PhD, technical lead for SIREN serology at the UK Health Security Agency (UKHSA), will present the work on Tuesday at the 2022 European Congress of Clinical Microbiology & Infectious Diseases (ECCMID), Lisbon.

In an interview, Dr. Otter noted that, “it is important to remember that antibody levels are only one aspect of the immune response, and in our recent vaccine effectiveness analysis, we found that dosing intervals did not affect protection against infection.”

The study, which appeared in the March issue of the New England Journal of Medicine, also found that after the second dose of vaccine, there was about a 2.5–fold difference in antibody levels between those who had prior infection of 16.052 (14.071-18.312) BAU/mL, compared with 7.050 (6.634-7.491) BAU/mL in infection-naive individuals (P < .0001).

Following the first dose only, antibody levels were up to 10 times higher in participants who were previously infected, compared with infection-naive individuals. This effect lasted up to 8 months and then began to plateau.
 

Natural infection increased antibody levels

Dr. Otter remarked that, “COVID-19 antibody levels are high in those people who were previously naturally infected and vaccinated, highlighting that vaccination provides an additional benefit to these individuals.”

This news organization asked Charlotte Thålin, PhD, an immunologist from the Karolinska Institute, Stockholm, to comment on the study. Dr. Thålin studies a cohort similar to SIREN, called the Swedish COMMUNITY health care worker cohort. “The new data from the SIREN emphasizes the importance of the number of antigenic exposures and the time interval between them, whether it be exposure through vaccination or exposure through infection.” 

“We see similar data in our Swedish COMMUNITY health care worker cohort,” Dr. Thålin continued, “where infection prior to vaccination yields a more than twofold enhancement in antibodies, neutralizing breadth, and T cell responses, and an even larger increase with a longer time interval between infection and vaccination.”

However, she cautioned that they now see a high rate of Omicron vaccine breakthrough infections, and this is also true in people with previous infection and three vaccine doses.

“As we approach a second booster – a fourth vaccine dose – we need to consider that many individuals will have had up to five to six antigen exposures within a short period of time, sometimes within a year,” she pointed out. “This is a whole new scenario, with a lot of different combinations of vaccine and infection-induced immunity. We do not yet know the impact of these frequent immune exposures, and we now need to monitor immune responses following Omicron and booster doses closely.”

SIREN originally aimed to understand how much protection people got after developing a primary infection and why they might become reinfected with COVID-19. Following the rollout of the United Kingdom’s vaccination program, the protective effects of vaccination against COVID-19 were investigated, as well as why some people still become ill after being vaccinated, Dr. Otter explained.

In this latest analysis, Dr. Otter and colleagues assessed anti-spike binding antibodies in serum samples from a total of 5,871 health care workers, with 3,989 after one dose (at least 21 days) and 1,882 after two doses (at least 14 days).

Most participants were women (82.3%), of White ethnicity (87%), and came from across the United Kingdom.

Participants were also categorized into those who had evidence of natural COVID-19 infection (confirmed by a PCR test or assumed because of their antibody profile) or those who were infection-naive. Almost all (> 99%) of those who were infection-naive seroconverted after vaccination.

The primary outcome was anti-spike antibody levels assessed according to dose, previous infection, dosing interval, age, ethnicity, and comorbidities, including immunosuppressive disease such as immune system cancers, rheumatologic disease, chronic respiratory diseases, diabetes, obesity, and chronic neurologic disease. 

In the infection-naive group, the mean antibody (anti-S titer) was 75.48 BAU/mL after the first vaccine dose, and this rose to 7,049.76 BAU/mL after the second dose.

The much higher antibody titer with the second dose in infection-naive individuals “is what gives you the most protection, as your antibody titers are at their peak. They then start to gradually wane from this peak,” said Dr. Otter.

In the post-infection group, antibody titers also rose (2,111.08 BAU/mL after first dose and 16,052.39 BAU/mL after second dose), although less so than in the infection-naive group, because of the additional exposure of infection, added Dr. Otter.

Antibody levels also varied according to time elapsed between natural infection and dose 1 of vaccination. With a 3-month interval, antibody levels were 1,970.83 (1,506.01-2,579.1) BAU/mL, compared with 13,759.31 (8,097.78-23,379.09) BAU/mL after a 9-month interval. Antibody levels after one dose in those previously infected are higher than the infection-naive because “previous infection, then vaccination, is likely explained by T-cell expansion upon a boost with a second antigen exposure, and then a maturing memory B-cell response that has been demonstrated up to 6 months,” explained Dr. Otter.

 

Timing of fourth dose

By March of this year, 86.2% of the U.K. population aged over 12 years had received at least two doses, but with rises in disease prevalence and the spread of variants of concern, further work is ongoing to understand the waning of the immune response, level of protection, and why some individuals develop COVID-19 even when double-vaccinated.

This news organization asked Susanna Dunachie, BMChB, professor of infectious diseases, University of Oxford, U.K., what the interval findings might mean for the timing of the fourth dose of vaccine across the U.K. population.

In the United Kingdom, fourth doses are being given to people who are 75 years and older, residents in care homes for older people, and those with weakened immune systems. “To make decisions about fourth doses for healthy people, we need to see how quickly antibody and T-cell responses drop,” said Ms. Dunachie, who is part of the large SIREN study team but was not involved in the analysis led by Dr. Otter. “Current research suggests that the T-cell response may be better maintained than the antibody response, and less affected by variants like Omicron.”

She explained the balance between antibody and T-cell responses to vaccination. “It is likely that antibodies that neutralize the virus are important for preventing any infection at all, and these unfortunately do fall in time, but T-cell responses are better sustained and help keep people out of [the] hospital,” she said.

Ms. Dunachie added that it was necessary to wait and observe what happens next with SARS-CoV-2 evolution, as well as wait for longer follow-up after the third dose in healthy people. “On current evidence, my estimate is we postpone decisions on fourth doses in healthy people to late summer/autumn.”

A version of this article first appeared on Medscape.com.

An overall ninefold increase in COVID-19 antibody levels can be seen with a longer interval between first and second doses of the Pfizer/BioNTech (BNT162b2) vaccine in people without prior infection, according to data from the U.K. government’s SIREN (SARS-CoV-2 Immunity and Reinfection Evaluation) study.

This interval-dependent antibody level varied by age, with those aged 45-54 years showing an 11-fold increase with a longer dosing interval (greater than 10 weeks vs. 2-4 weeks). People younger than age 25 years showed a 13-fold increase with the longer interval, but participant numbers were low in this sub-group.

Overall antibody levels in infection-naive participants were 1,268.72 Binding Antibody Units (BAU)/mL (1,043.25-1,542.91) in those with a 2-4–week interval, compared with 11,479.73 BAU/mL (10,742.78-12,267.24) (P < .0001), in those with at least a 10-week interval between doses.

The work is the latest analysis from SIREN, which measured antibody levels in the blood from nearly 6,000 health care workers from across the United Kingdom. Study lead Ashley Otter, PhD, technical lead for SIREN serology at the UK Health Security Agency (UKHSA), will present the work on Tuesday at the 2022 European Congress of Clinical Microbiology & Infectious Diseases (ECCMID), Lisbon.

In an interview, Dr. Otter noted that, “it is important to remember that antibody levels are only one aspect of the immune response, and in our recent vaccine effectiveness analysis, we found that dosing intervals did not affect protection against infection.”

The study, which appeared in the March issue of the New England Journal of Medicine, also found that after the second dose of vaccine, there was about a 2.5–fold difference in antibody levels between those who had prior infection of 16.052 (14.071-18.312) BAU/mL, compared with 7.050 (6.634-7.491) BAU/mL in infection-naive individuals (P < .0001).

Following the first dose only, antibody levels were up to 10 times higher in participants who were previously infected, compared with infection-naive individuals. This effect lasted up to 8 months and then began to plateau.
 

Natural infection increased antibody levels

Dr. Otter remarked that, “COVID-19 antibody levels are high in those people who were previously naturally infected and vaccinated, highlighting that vaccination provides an additional benefit to these individuals.”

This news organization asked Charlotte Thålin, PhD, an immunologist from the Karolinska Institute, Stockholm, to comment on the study. Dr. Thålin studies a cohort similar to SIREN, called the Swedish COMMUNITY health care worker cohort. “The new data from the SIREN emphasizes the importance of the number of antigenic exposures and the time interval between them, whether it be exposure through vaccination or exposure through infection.” 

“We see similar data in our Swedish COMMUNITY health care worker cohort,” Dr. Thålin continued, “where infection prior to vaccination yields a more than twofold enhancement in antibodies, neutralizing breadth, and T cell responses, and an even larger increase with a longer time interval between infection and vaccination.”

However, she cautioned that they now see a high rate of Omicron vaccine breakthrough infections, and this is also true in people with previous infection and three vaccine doses.

“As we approach a second booster – a fourth vaccine dose – we need to consider that many individuals will have had up to five to six antigen exposures within a short period of time, sometimes within a year,” she pointed out. “This is a whole new scenario, with a lot of different combinations of vaccine and infection-induced immunity. We do not yet know the impact of these frequent immune exposures, and we now need to monitor immune responses following Omicron and booster doses closely.”

SIREN originally aimed to understand how much protection people got after developing a primary infection and why they might become reinfected with COVID-19. Following the rollout of the United Kingdom’s vaccination program, the protective effects of vaccination against COVID-19 were investigated, as well as why some people still become ill after being vaccinated, Dr. Otter explained.

In this latest analysis, Dr. Otter and colleagues assessed anti-spike binding antibodies in serum samples from a total of 5,871 health care workers, with 3,989 after one dose (at least 21 days) and 1,882 after two doses (at least 14 days).

Most participants were women (82.3%), of White ethnicity (87%), and came from across the United Kingdom.

Participants were also categorized into those who had evidence of natural COVID-19 infection (confirmed by a PCR test or assumed because of their antibody profile) or those who were infection-naive. Almost all (> 99%) of those who were infection-naive seroconverted after vaccination.

The primary outcome was anti-spike antibody levels assessed according to dose, previous infection, dosing interval, age, ethnicity, and comorbidities, including immunosuppressive disease such as immune system cancers, rheumatologic disease, chronic respiratory diseases, diabetes, obesity, and chronic neurologic disease. 

In the infection-naive group, the mean antibody (anti-S titer) was 75.48 BAU/mL after the first vaccine dose, and this rose to 7,049.76 BAU/mL after the second dose.

The much higher antibody titer with the second dose in infection-naive individuals “is what gives you the most protection, as your antibody titers are at their peak. They then start to gradually wane from this peak,” said Dr. Otter.

In the post-infection group, antibody titers also rose (2,111.08 BAU/mL after first dose and 16,052.39 BAU/mL after second dose), although less so than in the infection-naive group, because of the additional exposure of infection, added Dr. Otter.

Antibody levels also varied according to time elapsed between natural infection and dose 1 of vaccination. With a 3-month interval, antibody levels were 1,970.83 (1,506.01-2,579.1) BAU/mL, compared with 13,759.31 (8,097.78-23,379.09) BAU/mL after a 9-month interval. Antibody levels after one dose in those previously infected are higher than the infection-naive because “previous infection, then vaccination, is likely explained by T-cell expansion upon a boost with a second antigen exposure, and then a maturing memory B-cell response that has been demonstrated up to 6 months,” explained Dr. Otter.

 

Timing of fourth dose

By March of this year, 86.2% of the U.K. population aged over 12 years had received at least two doses, but with rises in disease prevalence and the spread of variants of concern, further work is ongoing to understand the waning of the immune response, level of protection, and why some individuals develop COVID-19 even when double-vaccinated.

This news organization asked Susanna Dunachie, BMChB, professor of infectious diseases, University of Oxford, U.K., what the interval findings might mean for the timing of the fourth dose of vaccine across the U.K. population.

In the United Kingdom, fourth doses are being given to people who are 75 years and older, residents in care homes for older people, and those with weakened immune systems. “To make decisions about fourth doses for healthy people, we need to see how quickly antibody and T-cell responses drop,” said Ms. Dunachie, who is part of the large SIREN study team but was not involved in the analysis led by Dr. Otter. “Current research suggests that the T-cell response may be better maintained than the antibody response, and less affected by variants like Omicron.”

She explained the balance between antibody and T-cell responses to vaccination. “It is likely that antibodies that neutralize the virus are important for preventing any infection at all, and these unfortunately do fall in time, but T-cell responses are better sustained and help keep people out of [the] hospital,” she said.

Ms. Dunachie added that it was necessary to wait and observe what happens next with SARS-CoV-2 evolution, as well as wait for longer follow-up after the third dose in healthy people. “On current evidence, my estimate is we postpone decisions on fourth doses in healthy people to late summer/autumn.”

A version of this article first appeared on Medscape.com.

An overall ninefold increase in COVID-19 antibody levels can be seen with a longer interval between first and second doses of the Pfizer/BioNTech (BNT162b2) vaccine in people without prior infection, according to data from the U.K. government’s SIREN (SARS-CoV-2 Immunity and Reinfection Evaluation) study.

This interval-dependent antibody level varied by age, with those aged 45-54 years showing an 11-fold increase with a longer dosing interval (greater than 10 weeks vs. 2-4 weeks). People younger than age 25 years showed a 13-fold increase with the longer interval, but participant numbers were low in this sub-group.

Overall antibody levels in infection-naive participants were 1,268.72 Binding Antibody Units (BAU)/mL (1,043.25-1,542.91) in those with a 2-4–week interval, compared with 11,479.73 BAU/mL (10,742.78-12,267.24) (P < .0001), in those with at least a 10-week interval between doses.

The work is the latest analysis from SIREN, which measured antibody levels in the blood from nearly 6,000 health care workers from across the United Kingdom. Study lead Ashley Otter, PhD, technical lead for SIREN serology at the UK Health Security Agency (UKHSA), will present the work on Tuesday at the 2022 European Congress of Clinical Microbiology & Infectious Diseases (ECCMID), Lisbon.

In an interview, Dr. Otter noted that, “it is important to remember that antibody levels are only one aspect of the immune response, and in our recent vaccine effectiveness analysis, we found that dosing intervals did not affect protection against infection.”

The study, which appeared in the March issue of the New England Journal of Medicine, also found that after the second dose of vaccine, there was about a 2.5–fold difference in antibody levels between those who had prior infection of 16.052 (14.071-18.312) BAU/mL, compared with 7.050 (6.634-7.491) BAU/mL in infection-naive individuals (P < .0001).

Following the first dose only, antibody levels were up to 10 times higher in participants who were previously infected, compared with infection-naive individuals. This effect lasted up to 8 months and then began to plateau.
 

Natural infection increased antibody levels

Dr. Otter remarked that, “COVID-19 antibody levels are high in those people who were previously naturally infected and vaccinated, highlighting that vaccination provides an additional benefit to these individuals.”

This news organization asked Charlotte Thålin, PhD, an immunologist from the Karolinska Institute, Stockholm, to comment on the study. Dr. Thålin studies a cohort similar to SIREN, called the Swedish COMMUNITY health care worker cohort. “The new data from the SIREN emphasizes the importance of the number of antigenic exposures and the time interval between them, whether it be exposure through vaccination or exposure through infection.” 

“We see similar data in our Swedish COMMUNITY health care worker cohort,” Dr. Thålin continued, “where infection prior to vaccination yields a more than twofold enhancement in antibodies, neutralizing breadth, and T cell responses, and an even larger increase with a longer time interval between infection and vaccination.”

However, she cautioned that they now see a high rate of Omicron vaccine breakthrough infections, and this is also true in people with previous infection and three vaccine doses.

“As we approach a second booster – a fourth vaccine dose – we need to consider that many individuals will have had up to five to six antigen exposures within a short period of time, sometimes within a year,” she pointed out. “This is a whole new scenario, with a lot of different combinations of vaccine and infection-induced immunity. We do not yet know the impact of these frequent immune exposures, and we now need to monitor immune responses following Omicron and booster doses closely.”

SIREN originally aimed to understand how much protection people got after developing a primary infection and why they might become reinfected with COVID-19. Following the rollout of the United Kingdom’s vaccination program, the protective effects of vaccination against COVID-19 were investigated, as well as why some people still become ill after being vaccinated, Dr. Otter explained.

In this latest analysis, Dr. Otter and colleagues assessed anti-spike binding antibodies in serum samples from a total of 5,871 health care workers, with 3,989 after one dose (at least 21 days) and 1,882 after two doses (at least 14 days).

Most participants were women (82.3%), of White ethnicity (87%), and came from across the United Kingdom.

Participants were also categorized into those who had evidence of natural COVID-19 infection (confirmed by a PCR test or assumed because of their antibody profile) or those who were infection-naive. Almost all (> 99%) of those who were infection-naive seroconverted after vaccination.

The primary outcome was anti-spike antibody levels assessed according to dose, previous infection, dosing interval, age, ethnicity, and comorbidities, including immunosuppressive disease such as immune system cancers, rheumatologic disease, chronic respiratory diseases, diabetes, obesity, and chronic neurologic disease. 

In the infection-naive group, the mean antibody (anti-S titer) was 75.48 BAU/mL after the first vaccine dose, and this rose to 7,049.76 BAU/mL after the second dose.

The much higher antibody titer with the second dose in infection-naive individuals “is what gives you the most protection, as your antibody titers are at their peak. They then start to gradually wane from this peak,” said Dr. Otter.

In the post-infection group, antibody titers also rose (2,111.08 BAU/mL after first dose and 16,052.39 BAU/mL after second dose), although less so than in the infection-naive group, because of the additional exposure of infection, added Dr. Otter.

Antibody levels also varied according to time elapsed between natural infection and dose 1 of vaccination. With a 3-month interval, antibody levels were 1,970.83 (1,506.01-2,579.1) BAU/mL, compared with 13,759.31 (8,097.78-23,379.09) BAU/mL after a 9-month interval. Antibody levels after one dose in those previously infected are higher than the infection-naive because “previous infection, then vaccination, is likely explained by T-cell expansion upon a boost with a second antigen exposure, and then a maturing memory B-cell response that has been demonstrated up to 6 months,” explained Dr. Otter.

 

Timing of fourth dose

By March of this year, 86.2% of the U.K. population aged over 12 years had received at least two doses, but with rises in disease prevalence and the spread of variants of concern, further work is ongoing to understand the waning of the immune response, level of protection, and why some individuals develop COVID-19 even when double-vaccinated.

This news organization asked Susanna Dunachie, BMChB, professor of infectious diseases, University of Oxford, U.K., what the interval findings might mean for the timing of the fourth dose of vaccine across the U.K. population.

In the United Kingdom, fourth doses are being given to people who are 75 years and older, residents in care homes for older people, and those with weakened immune systems. “To make decisions about fourth doses for healthy people, we need to see how quickly antibody and T-cell responses drop,” said Ms. Dunachie, who is part of the large SIREN study team but was not involved in the analysis led by Dr. Otter. “Current research suggests that the T-cell response may be better maintained than the antibody response, and less affected by variants like Omicron.”

She explained the balance between antibody and T-cell responses to vaccination. “It is likely that antibodies that neutralize the virus are important for preventing any infection at all, and these unfortunately do fall in time, but T-cell responses are better sustained and help keep people out of [the] hospital,” she said.

Ms. Dunachie added that it was necessary to wait and observe what happens next with SARS-CoV-2 evolution, as well as wait for longer follow-up after the third dose in healthy people. “On current evidence, my estimate is we postpone decisions on fourth doses in healthy people to late summer/autumn.”

A version of this article first appeared on Medscape.com.

A widely approved vaccine for meningitis may provide up to 40% protection against gonorrhea in young adults and adolescents, according to new research. This moderate efficacy paired with a targeted risk-based approach could reduce cases as well as lead to health care savings over 10 years, an additional modeling study showed.

The results – in three linked papers – were published in The Lancet Infectious Diseases.

Gonorrhea, caused by the bacterium Neisseria gonorrhoeae, is the second most commonly reported sexually transmitted infection in the United States, according to the Centers for Disease Control and Prevention. Globally, the World Health Organization estimates that there were 82.4 million new cases in people aged 15-49 in 2020. At the same time, it is becoming more difficult to treat the infection because of the increasing prevalence of drug-resistant strains of N. gonorrhoeae.

“New approaches, such as vaccination, are needed as long-term strategies to prevent gonorrhea and address the emerging threat of antimicrobial resistance,” Winston Abara, MD, PhD, Division of STD Prevention, Centers for Disease Control and Prevention, and colleagues wrote.

While there is currently no vaccine for gonorrhea, observational studies have found an association between a meningococcal serogroup B vaccine and reduced gonorrhea cases. One study in New Zealand found that people vaccinated with the MeNZB vaccine, which was produced to control an outbreak of meningococcal disease in the country, were 31% less likely to contract gonorrhea.

This cross-reactivity comes about because Neisseria meningitidis, the bacterium that can cause meningitis, is closely related to N. gonorrhoeae, Joseph Alex Duncan, MD, PhD, associate professor of medicine, Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, said in an interview. He was not involved with the research. The thought is that “a large proportion of the proteins that are in the vaccine also recognize proteins from Neisseria gonorrhea, because the bacteria are so similar at the genetic level,” he said.

To see if this association was still found for the four-component serogroup B meningococcal vaccine (MenB-4C), which is now widely available, Dr. Abara and colleagues looked through health records to identify laboratory-confirmed gonorrhea and chlamydia infections in adolescents and young adults in New York City and Philadelphia. All individuals included in the analysis were age 16-23 and all infections occurred between Jan. 1, 2016, and Dec. 31, 2018. These infections were then linked to vaccination records to determine individuals’ MenB-4C vaccination status. Complete vaccination was defined as two MenB-4C doses, delivered 30-180 days apart.

The research team identified over 167,700 infections, including 18,099 gonococcal infections, 124,876 chlamydial infections, and 24,731 coinfections, among 109,737 individuals. A total of 7,692 individuals had received at least one shot of the vaccine, and 3,660 people were fully vaccinated. Full MenB-4C vaccination was estimated to be 40% protective (APR 0.60; P < .0001) against gonorrhea, and partial vaccination was 26% protective (APR 0.74; P = .0012).

“The findings of our study add to the body of evidence that demonstrates that the MenB-4C may offer cross-protection against Neisseria gonorrhoeae, and it supports feasibility of an effective gonococcal vaccine with implications for gonorrhea prevention and control,” Dr. Abara told this news organization.

A second study conducted in South Australia looked at the effectiveness of the MenB-4C vaccine against meningitis and gonorrhea as part of a vaccination program. Using infection data from the Government of South Australia and vaccination records from the Australian Immunization Register, researchers identified individuals born between Feb. 1, 1998, and Feb. 1, 2005, with a documented gonorrhea or chlamydia infection between Feb. 1, 2019, and Jan. 31, 2021. Individuals with chlamydia served as the controls to account for similar sexual behavioral risks.

The analysis included 512 individuals with 575 cases of gonorrhea and 3,140 individuals with 3,847 episodes of chlamydia. In this group, the estimated vaccine effectiveness against gonorrhea was 32.7% (95% confidence interval, 8.3-50.6) in individuals who were fully vaccinated and 32.6% (95% CI, 10.6-49.1) in those who had received at least one dose of the MenB-4C.

While these findings are “confirmatory” because they showed results similar to those in previous observational studies, they are still exciting, Dr. Duncan said. “Up until now, we really haven’t had any real progress in knowing what type of immune responses could actually be protective from the disease,” he said. “These observational studies have really reinvigorated the Neisseria gonorrhea vaccine research community.”

A vaccine with moderate efficacy – like the protection demonstrated in both studies – could lead to a significant reduction in cases, he noted. A 2015 Australian modeling study estimated that a nonwaning vaccine with 20% efficacy could reduce cases by 40% over 20 years. Focusing on vaccinating higher-risk groups could also have an “outsize impact,” said Jeanne Marrazzo, MD, director, Division of Infectious Diseases, UAB Medicine, Birmingham, Alabama, in an interview. In the third study published in The Lancet, researchers estimated the possible reduction of cases and the potential health care cost savings in England in a vaccination effort focusing on men who have sex with men (MSM) at high risk for gonorrhea infection. They predicted that a vaccine with 31% efficacy could prevent 110,200 cases in MSM and save about £8 million ($10.4 million) over 10 years.

Both Dr. Duncan and Dr. Marrazzo agreed that clinical trials are needed to tease out whether the decrease in gonorrhea cases is due to the MenB-4C vaccine or the association is incidental. There are two ongoing clinical trials, one in Australia and one in the United States. Dr. Marrazzo leads the U.S. multicenter study, which also has two locations in Bangkok. The trial will also look at whether vaccination protection varies by the location of gonococcal infection: urethra, rectum, cervix, or pharynx. The two new observational studies did not distinguish the different sites of infection.

Dr. Marrazzo’s trial has enrolled almost 500 individuals so far, with the goal of enrolling over 2,000 participants in total. She hopes to see results by late 2023. “It’s a pretty ambitious effort, but I’m hoping it will give us not only a definitive answer in terms of reduction in infection by anatomic site,” she said, but “also give us a lot of information about how the immune response works to protect you from getting gonorrhea if you do get the vaccine.”

Dr. Duncan has received research grants from the National Institutes of Health. Dr. Marrazzo leads a clinical trial of the MenB-4C vaccine sponsored by the National Institute of Allergy and Infectious Diseases.

A version of this article first appeared on Medscape.com.

A widely approved vaccine for meningitis may provide up to 40% protection against gonorrhea in young adults and adolescents, according to new research. This moderate efficacy paired with a targeted risk-based approach could reduce cases as well as lead to health care savings over 10 years, an additional modeling study showed.

The results – in three linked papers – were published in The Lancet Infectious Diseases.

Gonorrhea, caused by the bacterium Neisseria gonorrhoeae, is the second most commonly reported sexually transmitted infection in the United States, according to the Centers for Disease Control and Prevention. Globally, the World Health Organization estimates that there were 82.4 million new cases in people aged 15-49 in 2020. At the same time, it is becoming more difficult to treat the infection because of the increasing prevalence of drug-resistant strains of N. gonorrhoeae.

“New approaches, such as vaccination, are needed as long-term strategies to prevent gonorrhea and address the emerging threat of antimicrobial resistance,” Winston Abara, MD, PhD, Division of STD Prevention, Centers for Disease Control and Prevention, and colleagues wrote.

While there is currently no vaccine for gonorrhea, observational studies have found an association between a meningococcal serogroup B vaccine and reduced gonorrhea cases. One study in New Zealand found that people vaccinated with the MeNZB vaccine, which was produced to control an outbreak of meningococcal disease in the country, were 31% less likely to contract gonorrhea.

This cross-reactivity comes about because Neisseria meningitidis, the bacterium that can cause meningitis, is closely related to N. gonorrhoeae, Joseph Alex Duncan, MD, PhD, associate professor of medicine, Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, said in an interview. He was not involved with the research. The thought is that “a large proportion of the proteins that are in the vaccine also recognize proteins from Neisseria gonorrhea, because the bacteria are so similar at the genetic level,” he said.

To see if this association was still found for the four-component serogroup B meningococcal vaccine (MenB-4C), which is now widely available, Dr. Abara and colleagues looked through health records to identify laboratory-confirmed gonorrhea and chlamydia infections in adolescents and young adults in New York City and Philadelphia. All individuals included in the analysis were age 16-23 and all infections occurred between Jan. 1, 2016, and Dec. 31, 2018. These infections were then linked to vaccination records to determine individuals’ MenB-4C vaccination status. Complete vaccination was defined as two MenB-4C doses, delivered 30-180 days apart.

The research team identified over 167,700 infections, including 18,099 gonococcal infections, 124,876 chlamydial infections, and 24,731 coinfections, among 109,737 individuals. A total of 7,692 individuals had received at least one shot of the vaccine, and 3,660 people were fully vaccinated. Full MenB-4C vaccination was estimated to be 40% protective (APR 0.60; P < .0001) against gonorrhea, and partial vaccination was 26% protective (APR 0.74; P = .0012).

“The findings of our study add to the body of evidence that demonstrates that the MenB-4C may offer cross-protection against Neisseria gonorrhoeae, and it supports feasibility of an effective gonococcal vaccine with implications for gonorrhea prevention and control,” Dr. Abara told this news organization.

A second study conducted in South Australia looked at the effectiveness of the MenB-4C vaccine against meningitis and gonorrhea as part of a vaccination program. Using infection data from the Government of South Australia and vaccination records from the Australian Immunization Register, researchers identified individuals born between Feb. 1, 1998, and Feb. 1, 2005, with a documented gonorrhea or chlamydia infection between Feb. 1, 2019, and Jan. 31, 2021. Individuals with chlamydia served as the controls to account for similar sexual behavioral risks.

The analysis included 512 individuals with 575 cases of gonorrhea and 3,140 individuals with 3,847 episodes of chlamydia. In this group, the estimated vaccine effectiveness against gonorrhea was 32.7% (95% confidence interval, 8.3-50.6) in individuals who were fully vaccinated and 32.6% (95% CI, 10.6-49.1) in those who had received at least one dose of the MenB-4C.

While these findings are “confirmatory” because they showed results similar to those in previous observational studies, they are still exciting, Dr. Duncan said. “Up until now, we really haven’t had any real progress in knowing what type of immune responses could actually be protective from the disease,” he said. “These observational studies have really reinvigorated the Neisseria gonorrhea vaccine research community.”

A vaccine with moderate efficacy – like the protection demonstrated in both studies – could lead to a significant reduction in cases, he noted. A 2015 Australian modeling study estimated that a nonwaning vaccine with 20% efficacy could reduce cases by 40% over 20 years. Focusing on vaccinating higher-risk groups could also have an “outsize impact,” said Jeanne Marrazzo, MD, director, Division of Infectious Diseases, UAB Medicine, Birmingham, Alabama, in an interview. In the third study published in The Lancet, researchers estimated the possible reduction of cases and the potential health care cost savings in England in a vaccination effort focusing on men who have sex with men (MSM) at high risk for gonorrhea infection. They predicted that a vaccine with 31% efficacy could prevent 110,200 cases in MSM and save about £8 million ($10.4 million) over 10 years.

Both Dr. Duncan and Dr. Marrazzo agreed that clinical trials are needed to tease out whether the decrease in gonorrhea cases is due to the MenB-4C vaccine or the association is incidental. There are two ongoing clinical trials, one in Australia and one in the United States. Dr. Marrazzo leads the U.S. multicenter study, which also has two locations in Bangkok. The trial will also look at whether vaccination protection varies by the location of gonococcal infection: urethra, rectum, cervix, or pharynx. The two new observational studies did not distinguish the different sites of infection.

Dr. Marrazzo’s trial has enrolled almost 500 individuals so far, with the goal of enrolling over 2,000 participants in total. She hopes to see results by late 2023. “It’s a pretty ambitious effort, but I’m hoping it will give us not only a definitive answer in terms of reduction in infection by anatomic site,” she said, but “also give us a lot of information about how the immune response works to protect you from getting gonorrhea if you do get the vaccine.”

Dr. Duncan has received research grants from the National Institutes of Health. Dr. Marrazzo leads a clinical trial of the MenB-4C vaccine sponsored by the National Institute of Allergy and Infectious Diseases.

A version of this article first appeared on Medscape.com.

A widely approved vaccine for meningitis may provide up to 40% protection against gonorrhea in young adults and adolescents, according to new research. This moderate efficacy paired with a targeted risk-based approach could reduce cases as well as lead to health care savings over 10 years, an additional modeling study showed.

The results – in three linked papers – were published in The Lancet Infectious Diseases.

Gonorrhea, caused by the bacterium Neisseria gonorrhoeae, is the second most commonly reported sexually transmitted infection in the United States, according to the Centers for Disease Control and Prevention. Globally, the World Health Organization estimates that there were 82.4 million new cases in people aged 15-49 in 2020. At the same time, it is becoming more difficult to treat the infection because of the increasing prevalence of drug-resistant strains of N. gonorrhoeae.

“New approaches, such as vaccination, are needed as long-term strategies to prevent gonorrhea and address the emerging threat of antimicrobial resistance,” Winston Abara, MD, PhD, Division of STD Prevention, Centers for Disease Control and Prevention, and colleagues wrote.

While there is currently no vaccine for gonorrhea, observational studies have found an association between a meningococcal serogroup B vaccine and reduced gonorrhea cases. One study in New Zealand found that people vaccinated with the MeNZB vaccine, which was produced to control an outbreak of meningococcal disease in the country, were 31% less likely to contract gonorrhea.

This cross-reactivity comes about because Neisseria meningitidis, the bacterium that can cause meningitis, is closely related to N. gonorrhoeae, Joseph Alex Duncan, MD, PhD, associate professor of medicine, Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, said in an interview. He was not involved with the research. The thought is that “a large proportion of the proteins that are in the vaccine also recognize proteins from Neisseria gonorrhea, because the bacteria are so similar at the genetic level,” he said.

To see if this association was still found for the four-component serogroup B meningococcal vaccine (MenB-4C), which is now widely available, Dr. Abara and colleagues looked through health records to identify laboratory-confirmed gonorrhea and chlamydia infections in adolescents and young adults in New York City and Philadelphia. All individuals included in the analysis were age 16-23 and all infections occurred between Jan. 1, 2016, and Dec. 31, 2018. These infections were then linked to vaccination records to determine individuals’ MenB-4C vaccination status. Complete vaccination was defined as two MenB-4C doses, delivered 30-180 days apart.

The research team identified over 167,700 infections, including 18,099 gonococcal infections, 124,876 chlamydial infections, and 24,731 coinfections, among 109,737 individuals. A total of 7,692 individuals had received at least one shot of the vaccine, and 3,660 people were fully vaccinated. Full MenB-4C vaccination was estimated to be 40% protective (APR 0.60; P < .0001) against gonorrhea, and partial vaccination was 26% protective (APR 0.74; P = .0012).

“The findings of our study add to the body of evidence that demonstrates that the MenB-4C may offer cross-protection against Neisseria gonorrhoeae, and it supports feasibility of an effective gonococcal vaccine with implications for gonorrhea prevention and control,” Dr. Abara told this news organization.

A second study conducted in South Australia looked at the effectiveness of the MenB-4C vaccine against meningitis and gonorrhea as part of a vaccination program. Using infection data from the Government of South Australia and vaccination records from the Australian Immunization Register, researchers identified individuals born between Feb. 1, 1998, and Feb. 1, 2005, with a documented gonorrhea or chlamydia infection between Feb. 1, 2019, and Jan. 31, 2021. Individuals with chlamydia served as the controls to account for similar sexual behavioral risks.

The analysis included 512 individuals with 575 cases of gonorrhea and 3,140 individuals with 3,847 episodes of chlamydia. In this group, the estimated vaccine effectiveness against gonorrhea was 32.7% (95% confidence interval, 8.3-50.6) in individuals who were fully vaccinated and 32.6% (95% CI, 10.6-49.1) in those who had received at least one dose of the MenB-4C.

While these findings are “confirmatory” because they showed results similar to those in previous observational studies, they are still exciting, Dr. Duncan said. “Up until now, we really haven’t had any real progress in knowing what type of immune responses could actually be protective from the disease,” he said. “These observational studies have really reinvigorated the Neisseria gonorrhea vaccine research community.”

A vaccine with moderate efficacy – like the protection demonstrated in both studies – could lead to a significant reduction in cases, he noted. A 2015 Australian modeling study estimated that a nonwaning vaccine with 20% efficacy could reduce cases by 40% over 20 years. Focusing on vaccinating higher-risk groups could also have an “outsize impact,” said Jeanne Marrazzo, MD, director, Division of Infectious Diseases, UAB Medicine, Birmingham, Alabama, in an interview. In the third study published in The Lancet, researchers estimated the possible reduction of cases and the potential health care cost savings in England in a vaccination effort focusing on men who have sex with men (MSM) at high risk for gonorrhea infection. They predicted that a vaccine with 31% efficacy could prevent 110,200 cases in MSM and save about £8 million ($10.4 million) over 10 years.

Both Dr. Duncan and Dr. Marrazzo agreed that clinical trials are needed to tease out whether the decrease in gonorrhea cases is due to the MenB-4C vaccine or the association is incidental. There are two ongoing clinical trials, one in Australia and one in the United States. Dr. Marrazzo leads the U.S. multicenter study, which also has two locations in Bangkok. The trial will also look at whether vaccination protection varies by the location of gonococcal infection: urethra, rectum, cervix, or pharynx. The two new observational studies did not distinguish the different sites of infection.

Dr. Marrazzo’s trial has enrolled almost 500 individuals so far, with the goal of enrolling over 2,000 participants in total. She hopes to see results by late 2023. “It’s a pretty ambitious effort, but I’m hoping it will give us not only a definitive answer in terms of reduction in infection by anatomic site,” she said, but “also give us a lot of information about how the immune response works to protect you from getting gonorrhea if you do get the vaccine.”

Dr. Duncan has received research grants from the National Institutes of Health. Dr. Marrazzo leads a clinical trial of the MenB-4C vaccine sponsored by the National Institute of Allergy and Infectious Diseases.

A version of this article first appeared on Medscape.com.