Vaccines

A personalized messenger RNA (mRNA) vaccine for pancreatic cancer continues to show promise for improving patient survival, according to 6-year follow-up results of a phase 1 clinical study.

Among the 8 out of 16 patients in the study who initially experienced an immune response to the vaccine, seven (87.5%) were still alive at follow-up, lead investigator Vinod P. Balachandran, MD, reported at the American Association for Cancer Research (AACR) Annual Meeting 2026.

Of the eight patients who did not respond, two (25%) were still alive, with a median survival time of 3.4 years. “This suggests that personalized vaccines can stimulate the immune system in some pancreatic cancer patients, and that these patients continue to do well for several years after vaccination,” said Balachandran, director of the Olayan Center for Cancer Vaccines at Memorial Sloan Kettering Cancer Center in New York City.

The findings suggest that this vaccine has the potential to improve outcomes in patients with pancreatic cancer, which is one of the deadliest cancers, he said.

The 5-year survival rate for pancreatic cancer is currently 13%, according to the American Cancer Society’s Cancer Statistics 2026 report.

Initial results of the trial evaluating the individualized neoantigen vaccine — autogene cevumeran, which is being developed by BioNTech and Genentech — were published in Nature in February 2025.

After pancreatic cancer surgery and chemo-immunotherapy, patients with pancreatic ductal adenocarcinoma (PDAC) received a vaccine personalized to each patient based on unique changes in their tumor DNA.

The eight patients with vaccine-induced T cells had prolonged recurrence-free survival (RFS; median not reached), whereas nonresponders had a median RFS of 13.4 months, the authors had reported in the Nature paper.

This correlation was not confounded by other factors, including those associated with the patient, tumor, treatment, and host immune fitness, Balachandran noted.

In the responders, the T-cell clones had “high magnitude and exceptional longevity,” with an average estimated lifespan of 7.7 years, he said.

A fundamental challenge in developing cancer vaccines has been generating durable functional T cells specific for tumor antigens, and these findings suggest that mRNA-lipoplex vaccines against somatic mutation-derived neoantigens like autogene cevumeran may help overcome this challenge in pancreatic cancer, he and his colleagues concluded in the Nature paper.

The latest findings presented at the AACR annual meeting further underscore the potential of this approach.

At the 6-year follow-up, median RFS was “still not reached” in the vaccine responders vs 1.1 year in the nonresponders, he noted.

“This translates to a difference in overall survival,” he said. “Seven of eight [responders to the vaccine] are still alive 4.5-6 years after surgery.”

And of the 2 of 8 nonresponders still alive, one appears to be mounting a subclinical vaccine-induced T-cell response, he added, noting that this “suggests that inducible vaccine immunity may also impact survival in PDAC.”

“The implication here, we believe, is that even if a cancer has very mutational by-products [like PDAC], these mutational by-products can empower potent and composite immunity,” he said. “This is important because it could potentially expand vaccine eligibility to many cancers.”

Currently, there are about 50 neoantigen vaccine trials in solid tumors ongoing worldwide, he noted.

Memorial Sloan Kettering reports that Genentech and BioNTech are now testing autogene cevumeran in a larger patient population at numerous sites worldwide.

Balachandran reported receiving research support from Genentech, Merck Sharp & Dohme, and AbbVie.

Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape, MDedge, and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at sworcester@mdedge.com or on X: @SW_MedReporter.

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

A personalized messenger RNA (mRNA) vaccine for pancreatic cancer continues to show promise for improving patient survival, according to 6-year follow-up results of a phase 1 clinical study.

Among the 8 out of 16 patients in the study who initially experienced an immune response to the vaccine, seven (87.5%) were still alive at follow-up, lead investigator Vinod P. Balachandran, MD, reported at the American Association for Cancer Research (AACR) Annual Meeting 2026.

Of the eight patients who did not respond, two (25%) were still alive, with a median survival time of 3.4 years. “This suggests that personalized vaccines can stimulate the immune system in some pancreatic cancer patients, and that these patients continue to do well for several years after vaccination,” said Balachandran, director of the Olayan Center for Cancer Vaccines at Memorial Sloan Kettering Cancer Center in New York City.

The findings suggest that this vaccine has the potential to improve outcomes in patients with pancreatic cancer, which is one of the deadliest cancers, he said.

The 5-year survival rate for pancreatic cancer is currently 13%, according to the American Cancer Society’s Cancer Statistics 2026 report.

Initial results of the trial evaluating the individualized neoantigen vaccine — autogene cevumeran, which is being developed by BioNTech and Genentech — were published in Nature in February 2025.

After pancreatic cancer surgery and chemo-immunotherapy, patients with pancreatic ductal adenocarcinoma (PDAC) received a vaccine personalized to each patient based on unique changes in their tumor DNA.

The eight patients with vaccine-induced T cells had prolonged recurrence-free survival (RFS; median not reached), whereas nonresponders had a median RFS of 13.4 months, the authors had reported in the Nature paper.

This correlation was not confounded by other factors, including those associated with the patient, tumor, treatment, and host immune fitness, Balachandran noted.

In the responders, the T-cell clones had “high magnitude and exceptional longevity,” with an average estimated lifespan of 7.7 years, he said.

A fundamental challenge in developing cancer vaccines has been generating durable functional T cells specific for tumor antigens, and these findings suggest that mRNA-lipoplex vaccines against somatic mutation-derived neoantigens like autogene cevumeran may help overcome this challenge in pancreatic cancer, he and his colleagues concluded in the Nature paper.

The latest findings presented at the AACR annual meeting further underscore the potential of this approach.

At the 6-year follow-up, median RFS was “still not reached” in the vaccine responders vs 1.1 year in the nonresponders, he noted.

“This translates to a difference in overall survival,” he said. “Seven of eight [responders to the vaccine] are still alive 4.5-6 years after surgery.”

And of the 2 of 8 nonresponders still alive, one appears to be mounting a subclinical vaccine-induced T-cell response, he added, noting that this “suggests that inducible vaccine immunity may also impact survival in PDAC.”

“The implication here, we believe, is that even if a cancer has very mutational by-products [like PDAC], these mutational by-products can empower potent and composite immunity,” he said. “This is important because it could potentially expand vaccine eligibility to many cancers.”

Currently, there are about 50 neoantigen vaccine trials in solid tumors ongoing worldwide, he noted.

Memorial Sloan Kettering reports that Genentech and BioNTech are now testing autogene cevumeran in a larger patient population at numerous sites worldwide.

Balachandran reported receiving research support from Genentech, Merck Sharp & Dohme, and AbbVie.

Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape, MDedge, and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at sworcester@mdedge.com or on X: @SW_MedReporter.

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

A personalized messenger RNA (mRNA) vaccine for pancreatic cancer continues to show promise for improving patient survival, according to 6-year follow-up results of a phase 1 clinical study.

Among the 8 out of 16 patients in the study who initially experienced an immune response to the vaccine, seven (87.5%) were still alive at follow-up, lead investigator Vinod P. Balachandran, MD, reported at the American Association for Cancer Research (AACR) Annual Meeting 2026.

Of the eight patients who did not respond, two (25%) were still alive, with a median survival time of 3.4 years. “This suggests that personalized vaccines can stimulate the immune system in some pancreatic cancer patients, and that these patients continue to do well for several years after vaccination,” said Balachandran, director of the Olayan Center for Cancer Vaccines at Memorial Sloan Kettering Cancer Center in New York City.

The findings suggest that this vaccine has the potential to improve outcomes in patients with pancreatic cancer, which is one of the deadliest cancers, he said.

The 5-year survival rate for pancreatic cancer is currently 13%, according to the American Cancer Society’s Cancer Statistics 2026 report.

Initial results of the trial evaluating the individualized neoantigen vaccine — autogene cevumeran, which is being developed by BioNTech and Genentech — were published in Nature in February 2025.

After pancreatic cancer surgery and chemo-immunotherapy, patients with pancreatic ductal adenocarcinoma (PDAC) received a vaccine personalized to each patient based on unique changes in their tumor DNA.

The eight patients with vaccine-induced T cells had prolonged recurrence-free survival (RFS; median not reached), whereas nonresponders had a median RFS of 13.4 months, the authors had reported in the Nature paper.

This correlation was not confounded by other factors, including those associated with the patient, tumor, treatment, and host immune fitness, Balachandran noted.

In the responders, the T-cell clones had “high magnitude and exceptional longevity,” with an average estimated lifespan of 7.7 years, he said.

A fundamental challenge in developing cancer vaccines has been generating durable functional T cells specific for tumor antigens, and these findings suggest that mRNA-lipoplex vaccines against somatic mutation-derived neoantigens like autogene cevumeran may help overcome this challenge in pancreatic cancer, he and his colleagues concluded in the Nature paper.

The latest findings presented at the AACR annual meeting further underscore the potential of this approach.

At the 6-year follow-up, median RFS was “still not reached” in the vaccine responders vs 1.1 year in the nonresponders, he noted.

“This translates to a difference in overall survival,” he said. “Seven of eight [responders to the vaccine] are still alive 4.5-6 years after surgery.”

And of the 2 of 8 nonresponders still alive, one appears to be mounting a subclinical vaccine-induced T-cell response, he added, noting that this “suggests that inducible vaccine immunity may also impact survival in PDAC.”

“The implication here, we believe, is that even if a cancer has very mutational by-products [like PDAC], these mutational by-products can empower potent and composite immunity,” he said. “This is important because it could potentially expand vaccine eligibility to many cancers.”

Currently, there are about 50 neoantigen vaccine trials in solid tumors ongoing worldwide, he noted.

Memorial Sloan Kettering reports that Genentech and BioNTech are now testing autogene cevumeran in a larger patient population at numerous sites worldwide.

Balachandran reported receiving research support from Genentech, Merck Sharp & Dohme, and AbbVie.

Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape, MDedge, and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at sworcester@mdedge.com or on X: @SW_MedReporter.

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

Patients with advanced cancer treated with immune checkpoint inhibitors appear to have a survival benefit if they receive influenza vaccination, a new retrospective analysis found. The results also suggest no increase in the risk for immune-related adverse events (IRAEs) in these patients and that the improvement in survival outcomes may be stronger among those with cutaneous malignant melanoma.

“Our findings align with a growing body of evidence, mainly from retrospective studies, that suggest a potential association between influenza vaccination during immune checkpoint inhibitor treatment and improved survival among patients with cancer,” wrote senior author Antonis Valachis, MD, PhD, and colleagues in an article published in JCO Clinical Practice on February 9. “An additional clinically relevant observation is that the association between influenza vaccination and survival may vary by tumor type.”

The new research supports “current recommendations to offer influenza vaccination to all patients undergoing cancer therapy, including those receiving the drugs,” Valachis, of the Department of Oncology, Örebro University in Örebro, Sweden, and his coauthors wrote.

“What we observed is that influenza vaccination is safe for patients under immunotherapy treatment,” Valachis told Medscape Medical News. But “whether influenza vaccination can be used to boost immunotherapy effectiveness should be tested in a study with a different design,” such as a prospective interventional trial.

Discussing potential explanations for why influenza vaccination could affect immunotherapy outcomes without affecting rates of IRAEs, Valachis said that this “cannot be answered within the constraints of our study design, since all patients were treated with immunotherapy.”

It may nevertheless be hypothesized that “immune activation triggered by vaccination preferentially stimulates immune mechanisms that enhance immunotherapy efficacy, while sparing those that contribute to IRAEs.”

Steady Was 'Relatively Modestly Sized'

Question marks were raised over the study itself and, as a result, its findings.

Justin Jee, MD, PhD, a thoracic medical oncologist at Memorial Sloan Kettering Cancer Center, New York City, told Medscape Medical News that there are “a lot of challenges when looking at retrospective data.”

“The authors did a very reasonable job of trying to control for confounders and certain time dependent issues, like immortality bias,” he said. “That said, it’s a relatively modestly sized retrospective study for looking at something that has enormous potential for confounding bias that really can’t be captured with any standard statistical method.”

Jee pointed to factors such as providers potentially being more likely to refer people for vaccination if they’re healthier “vs if the patient is in hospice care,” or individuals simply not getting vaccinated because it is not uppermost in their mind.

“Those things are very, very difficult to control for.”

Jee also said he believes the benefit with influenza vaccination being stronger in cutaneous malignant melanoma could be a study artifact, while the lack of difference in rates of IRAEs could be the result of selection bias, but “it’s just impossible to say with a study like this.”

“I’ve seen several studies looking at both COVID and flu vaccines and whether or not they improve immune checkpoint blockade efficacy,” he added, explaining that “some of them say COVID vaccine good, flu vaccine not as good; others say both flu and COVID vaccines good; others say flu vaccine good, COVID vaccine not as good.”

All Patients With Cancer Should Be Vaccinated

What is clear is that “patients with cancer are [at] especially high risk of developing complications from viral illnesses, including flu, including COVID, and vaccines are a very important part of reducing morbidity, mortality, and spread,” Jee said. The “big picture” is that everyone should get the influenza vaccine, especially patients with cancer, “so in that sense I agree with that part of the conclusion of the paper” and that’s “an important message.”

Mini Kamboj, MD, chief medical epidemiologist at Memorial Sloan Kettering Cancer Center, agreed, saying that the results are “consistent with other research showing that vaccines are safe and beneficial for patients on checkpoint inhibitors.”

“While vaccinated patients with melanoma showed the greatest survival benefit, the authors note small sample size and unrecognized differences between the groups as a potential explanation for their findings. This does not change vaccine recommendations as evidence already supports flu vaccine safety and effectiveness in people with lung cancer on checkpoint inhibitors.”

Nearly 600 Patients With Advanced Cancer

The researchers performed a retrospective cohort study of patients from three regions in Sweden who had advanced solid tumors and were treated with PD-1 or PD-L1 inhibitor monotherapy, or PD-1 combination therapy with a cytotoxic T-lymphocyte-associated protein 4 inhibitor, between January 1, 2016, until December 31, 2021. Treatment was given either routinely or as part of a clinical trial.

Electronic medical records were examined to gather data on a range of variables, including age at diagnosis, sex, Charlson Comorbidity Index, type of cancer, primary treatment at diagnosis, number of previous lines of treatment, best treatment response, IRAEs, influenza vaccination status, and date and cause of death.

In all, 587 patients were treated with immune checkpoint inhibition over the study period. They had a median age of 66 years, and 58.1% were men. The most common malignancies were nonsmall cell lung cancer (NSCLC), cutaneous malignant melanoma (32.5%), and renal cell carcinoma (14.7%).

The most commonly used immune checkpoint inhibitor was nivolumab, which was administered to 47.9% of patients, followed by pembrolizumab (34.6%), atezolizumab (9.4%), and nivolumab plus ipilimumab (6.8%).

Only Patients With Malignant Melanoma Benefit

Over the study period, 17.7% of patients underwent influenza vaccination, at a median time between initiation of immune checkpoint inhibition and vaccination of 2 months. Ninety per cent of patients received the vaccine within 9 months of starting treatment.

Time-dependent Cox regression analysis revealed that real-world progression-free survival (rwPFS) was significantly longer with vaccinated patients than unvaccinated patients at a hazard ratio of 0.59 (95% CI, 0.44-0.79), as was overall survival, at a hazard ratio of 0.56 (95% CI, 0.42-0.75).

There was no significant difference in rwPFS and overall survival between vaccinated and unvaccinated patients among those with NSCLC, but significant differences were seen in those with cutaneous malignant melanoma, at hazard ratios of 0.58 (95% CI, 0.36-0.96) and 0.58 (95% CI, 0.36-0.96), respectively.

Restricting the analysis to immune checkpoint inhibitor monotherapy indicated that vaccinated patients had significantly longer rwPFS and overall survival than unvaccinated patients, at hazard ratios of 0.58 (95% CI, 0.43-0.79) and 0.50 (95% CI, 0.38-0.76), respectively.

Finally, the team found that there were no significant differences in the rates of any grade IRAEs between vaccinated and unvaccinated patients, at 48.4% vs 51.2% (P = .455), or in rates of multiple IRAEs, at 15.1% vs 19.2% (P = .297). The therapeutic management and outcomes of IRAEs were also comparable.

No funding or relevant financial relationships were declared.

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

Patients with advanced cancer treated with immune checkpoint inhibitors appear to have a survival benefit if they receive influenza vaccination, a new retrospective analysis found. The results also suggest no increase in the risk for immune-related adverse events (IRAEs) in these patients and that the improvement in survival outcomes may be stronger among those with cutaneous malignant melanoma.

“Our findings align with a growing body of evidence, mainly from retrospective studies, that suggest a potential association between influenza vaccination during immune checkpoint inhibitor treatment and improved survival among patients with cancer,” wrote senior author Antonis Valachis, MD, PhD, and colleagues in an article published in JCO Clinical Practice on February 9. “An additional clinically relevant observation is that the association between influenza vaccination and survival may vary by tumor type.”

The new research supports “current recommendations to offer influenza vaccination to all patients undergoing cancer therapy, including those receiving the drugs,” Valachis, of the Department of Oncology, Örebro University in Örebro, Sweden, and his coauthors wrote.

“What we observed is that influenza vaccination is safe for patients under immunotherapy treatment,” Valachis told Medscape Medical News. But “whether influenza vaccination can be used to boost immunotherapy effectiveness should be tested in a study with a different design,” such as a prospective interventional trial.

Discussing potential explanations for why influenza vaccination could affect immunotherapy outcomes without affecting rates of IRAEs, Valachis said that this “cannot be answered within the constraints of our study design, since all patients were treated with immunotherapy.”

It may nevertheless be hypothesized that “immune activation triggered by vaccination preferentially stimulates immune mechanisms that enhance immunotherapy efficacy, while sparing those that contribute to IRAEs.”

Steady Was 'Relatively Modestly Sized'

Question marks were raised over the study itself and, as a result, its findings.

Justin Jee, MD, PhD, a thoracic medical oncologist at Memorial Sloan Kettering Cancer Center, New York City, told Medscape Medical News that there are “a lot of challenges when looking at retrospective data.”

“The authors did a very reasonable job of trying to control for confounders and certain time dependent issues, like immortality bias,” he said. “That said, it’s a relatively modestly sized retrospective study for looking at something that has enormous potential for confounding bias that really can’t be captured with any standard statistical method.”

Jee pointed to factors such as providers potentially being more likely to refer people for vaccination if they’re healthier “vs if the patient is in hospice care,” or individuals simply not getting vaccinated because it is not uppermost in their mind.

“Those things are very, very difficult to control for.”

Jee also said he believes the benefit with influenza vaccination being stronger in cutaneous malignant melanoma could be a study artifact, while the lack of difference in rates of IRAEs could be the result of selection bias, but “it’s just impossible to say with a study like this.”

“I’ve seen several studies looking at both COVID and flu vaccines and whether or not they improve immune checkpoint blockade efficacy,” he added, explaining that “some of them say COVID vaccine good, flu vaccine not as good; others say both flu and COVID vaccines good; others say flu vaccine good, COVID vaccine not as good.”

All Patients With Cancer Should Be Vaccinated

What is clear is that “patients with cancer are [at] especially high risk of developing complications from viral illnesses, including flu, including COVID, and vaccines are a very important part of reducing morbidity, mortality, and spread,” Jee said. The “big picture” is that everyone should get the influenza vaccine, especially patients with cancer, “so in that sense I agree with that part of the conclusion of the paper” and that’s “an important message.”

Mini Kamboj, MD, chief medical epidemiologist at Memorial Sloan Kettering Cancer Center, agreed, saying that the results are “consistent with other research showing that vaccines are safe and beneficial for patients on checkpoint inhibitors.”

“While vaccinated patients with melanoma showed the greatest survival benefit, the authors note small sample size and unrecognized differences between the groups as a potential explanation for their findings. This does not change vaccine recommendations as evidence already supports flu vaccine safety and effectiveness in people with lung cancer on checkpoint inhibitors.”

Nearly 600 Patients With Advanced Cancer

The researchers performed a retrospective cohort study of patients from three regions in Sweden who had advanced solid tumors and were treated with PD-1 or PD-L1 inhibitor monotherapy, or PD-1 combination therapy with a cytotoxic T-lymphocyte-associated protein 4 inhibitor, between January 1, 2016, until December 31, 2021. Treatment was given either routinely or as part of a clinical trial.

Electronic medical records were examined to gather data on a range of variables, including age at diagnosis, sex, Charlson Comorbidity Index, type of cancer, primary treatment at diagnosis, number of previous lines of treatment, best treatment response, IRAEs, influenza vaccination status, and date and cause of death.

In all, 587 patients were treated with immune checkpoint inhibition over the study period. They had a median age of 66 years, and 58.1% were men. The most common malignancies were nonsmall cell lung cancer (NSCLC), cutaneous malignant melanoma (32.5%), and renal cell carcinoma (14.7%).

The most commonly used immune checkpoint inhibitor was nivolumab, which was administered to 47.9% of patients, followed by pembrolizumab (34.6%), atezolizumab (9.4%), and nivolumab plus ipilimumab (6.8%).

Only Patients With Malignant Melanoma Benefit

Over the study period, 17.7% of patients underwent influenza vaccination, at a median time between initiation of immune checkpoint inhibition and vaccination of 2 months. Ninety per cent of patients received the vaccine within 9 months of starting treatment.

Time-dependent Cox regression analysis revealed that real-world progression-free survival (rwPFS) was significantly longer with vaccinated patients than unvaccinated patients at a hazard ratio of 0.59 (95% CI, 0.44-0.79), as was overall survival, at a hazard ratio of 0.56 (95% CI, 0.42-0.75).

There was no significant difference in rwPFS and overall survival between vaccinated and unvaccinated patients among those with NSCLC, but significant differences were seen in those with cutaneous malignant melanoma, at hazard ratios of 0.58 (95% CI, 0.36-0.96) and 0.58 (95% CI, 0.36-0.96), respectively.

Restricting the analysis to immune checkpoint inhibitor monotherapy indicated that vaccinated patients had significantly longer rwPFS and overall survival than unvaccinated patients, at hazard ratios of 0.58 (95% CI, 0.43-0.79) and 0.50 (95% CI, 0.38-0.76), respectively.

Finally, the team found that there were no significant differences in the rates of any grade IRAEs between vaccinated and unvaccinated patients, at 48.4% vs 51.2% (P = .455), or in rates of multiple IRAEs, at 15.1% vs 19.2% (P = .297). The therapeutic management and outcomes of IRAEs were also comparable.

No funding or relevant financial relationships were declared.

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

Patients with advanced cancer treated with immune checkpoint inhibitors appear to have a survival benefit if they receive influenza vaccination, a new retrospective analysis found. The results also suggest no increase in the risk for immune-related adverse events (IRAEs) in these patients and that the improvement in survival outcomes may be stronger among those with cutaneous malignant melanoma.

“Our findings align with a growing body of evidence, mainly from retrospective studies, that suggest a potential association between influenza vaccination during immune checkpoint inhibitor treatment and improved survival among patients with cancer,” wrote senior author Antonis Valachis, MD, PhD, and colleagues in an article published in JCO Clinical Practice on February 9. “An additional clinically relevant observation is that the association between influenza vaccination and survival may vary by tumor type.”

The new research supports “current recommendations to offer influenza vaccination to all patients undergoing cancer therapy, including those receiving the drugs,” Valachis, of the Department of Oncology, Örebro University in Örebro, Sweden, and his coauthors wrote.

“What we observed is that influenza vaccination is safe for patients under immunotherapy treatment,” Valachis told Medscape Medical News. But “whether influenza vaccination can be used to boost immunotherapy effectiveness should be tested in a study with a different design,” such as a prospective interventional trial.

Discussing potential explanations for why influenza vaccination could affect immunotherapy outcomes without affecting rates of IRAEs, Valachis said that this “cannot be answered within the constraints of our study design, since all patients were treated with immunotherapy.”

It may nevertheless be hypothesized that “immune activation triggered by vaccination preferentially stimulates immune mechanisms that enhance immunotherapy efficacy, while sparing those that contribute to IRAEs.”

Steady Was 'Relatively Modestly Sized'

Question marks were raised over the study itself and, as a result, its findings.

Justin Jee, MD, PhD, a thoracic medical oncologist at Memorial Sloan Kettering Cancer Center, New York City, told Medscape Medical News that there are “a lot of challenges when looking at retrospective data.”

“The authors did a very reasonable job of trying to control for confounders and certain time dependent issues, like immortality bias,” he said. “That said, it’s a relatively modestly sized retrospective study for looking at something that has enormous potential for confounding bias that really can’t be captured with any standard statistical method.”

Jee pointed to factors such as providers potentially being more likely to refer people for vaccination if they’re healthier “vs if the patient is in hospice care,” or individuals simply not getting vaccinated because it is not uppermost in their mind.

“Those things are very, very difficult to control for.”

Jee also said he believes the benefit with influenza vaccination being stronger in cutaneous malignant melanoma could be a study artifact, while the lack of difference in rates of IRAEs could be the result of selection bias, but “it’s just impossible to say with a study like this.”

“I’ve seen several studies looking at both COVID and flu vaccines and whether or not they improve immune checkpoint blockade efficacy,” he added, explaining that “some of them say COVID vaccine good, flu vaccine not as good; others say both flu and COVID vaccines good; others say flu vaccine good, COVID vaccine not as good.”

All Patients With Cancer Should Be Vaccinated

What is clear is that “patients with cancer are [at] especially high risk of developing complications from viral illnesses, including flu, including COVID, and vaccines are a very important part of reducing morbidity, mortality, and spread,” Jee said. The “big picture” is that everyone should get the influenza vaccine, especially patients with cancer, “so in that sense I agree with that part of the conclusion of the paper” and that’s “an important message.”

Mini Kamboj, MD, chief medical epidemiologist at Memorial Sloan Kettering Cancer Center, agreed, saying that the results are “consistent with other research showing that vaccines are safe and beneficial for patients on checkpoint inhibitors.”

“While vaccinated patients with melanoma showed the greatest survival benefit, the authors note small sample size and unrecognized differences between the groups as a potential explanation for their findings. This does not change vaccine recommendations as evidence already supports flu vaccine safety and effectiveness in people with lung cancer on checkpoint inhibitors.”

Nearly 600 Patients With Advanced Cancer

The researchers performed a retrospective cohort study of patients from three regions in Sweden who had advanced solid tumors and were treated with PD-1 or PD-L1 inhibitor monotherapy, or PD-1 combination therapy with a cytotoxic T-lymphocyte-associated protein 4 inhibitor, between January 1, 2016, until December 31, 2021. Treatment was given either routinely or as part of a clinical trial.

Electronic medical records were examined to gather data on a range of variables, including age at diagnosis, sex, Charlson Comorbidity Index, type of cancer, primary treatment at diagnosis, number of previous lines of treatment, best treatment response, IRAEs, influenza vaccination status, and date and cause of death.

In all, 587 patients were treated with immune checkpoint inhibition over the study period. They had a median age of 66 years, and 58.1% were men. The most common malignancies were nonsmall cell lung cancer (NSCLC), cutaneous malignant melanoma (32.5%), and renal cell carcinoma (14.7%).

The most commonly used immune checkpoint inhibitor was nivolumab, which was administered to 47.9% of patients, followed by pembrolizumab (34.6%), atezolizumab (9.4%), and nivolumab plus ipilimumab (6.8%).

Only Patients With Malignant Melanoma Benefit

Over the study period, 17.7% of patients underwent influenza vaccination, at a median time between initiation of immune checkpoint inhibition and vaccination of 2 months. Ninety per cent of patients received the vaccine within 9 months of starting treatment.

Time-dependent Cox regression analysis revealed that real-world progression-free survival (rwPFS) was significantly longer with vaccinated patients than unvaccinated patients at a hazard ratio of 0.59 (95% CI, 0.44-0.79), as was overall survival, at a hazard ratio of 0.56 (95% CI, 0.42-0.75).

There was no significant difference in rwPFS and overall survival between vaccinated and unvaccinated patients among those with NSCLC, but significant differences were seen in those with cutaneous malignant melanoma, at hazard ratios of 0.58 (95% CI, 0.36-0.96) and 0.58 (95% CI, 0.36-0.96), respectively.

Restricting the analysis to immune checkpoint inhibitor monotherapy indicated that vaccinated patients had significantly longer rwPFS and overall survival than unvaccinated patients, at hazard ratios of 0.58 (95% CI, 0.43-0.79) and 0.50 (95% CI, 0.38-0.76), respectively.

Finally, the team found that there were no significant differences in the rates of any grade IRAEs between vaccinated and unvaccinated patients, at 48.4% vs 51.2% (P = .455), or in rates of multiple IRAEs, at 15.1% vs 19.2% (P = .297). The therapeutic management and outcomes of IRAEs were also comparable.

No funding or relevant financial relationships were declared.

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

TOPLINE:

A single dose of respiratory syncytial virus (RSV) vaccine provided protection against RSV illness and associated health care use in nearly 290,000 older US veterans over 2 respiratory illness seasons compared with unvaccinated individuals; however, protection declined over time, particularly among immunocompromised individuals.

METHODOLOGY:

• Researchers emulated a target trial to assess the long-term effectiveness of a single does of RSV vaccine, administered between September 2023 and March 2024, to prevent RSV infection and associated health care use among older US veterans.
• The primary outcome was any positive RSV test from 14 days after vaccination; secondary outcomes included RSV-associated emergency department or urgent care visits, hospitalizations, and ICU admissions.
• The median follow-up duration, measured from 14 days after vaccination, was 15.8 months, with a maximum of 19.0 months.

TAKEAWAY:

• The estimated vaccines effectiveness against RSV infection decreased from 82.5% (95% CI, 77.5%-86.9%) over 0 to 1 month to 59.4% (95% CI, 55.6%-63.5%) over 0 to 18 months of follow-up.
• Protection against RSV-associated emergency department and urgent care visits fell from 84.9% over 0 to 1 month to 60.6% over 0 to 18 months, and the estimated effectiveness against hospitalizations decreased from 88.9% to 57.3% over the same interval.
• The estimated effectiveness against RSV-associated ICU admissions reduced from 92.5% (95% CI, 61.1%-100%) over 0 to 1 month to 71.9% (95% CI, 42.8%-90.0%) over 0 to 18 months.
• Among immunocompromised individuals, protection against RSV infection showed the largest decline from 75.2% at 0 to 1 month to 39.7% over 18 months.

IN PRACTICE:

"Boosters may be needed, but for now, our efforts should be focused on saving lives and decreasing disease by encouraging vaccination of persons 75 years and older and those 60 years and older with underlying health issues," experts wrote in an accompanying editorial.

SOURCE:

The study was led by Kristina L. Bajema, MD, Veterans Affairs Portland Health Care System, Portland, Oregon. It was published online on November 24, 2025, in JAMA Internal Medicine.

LIMITATIONS:

RSV documentation may have been incomplete for veterans who sought care outside the Veterans Health Administration. The cohort was predominantly White men, limiting generalizability. Residual confounding could not be excluded. Estimates of long-term effectiveness should be interpreted cautiously because they reflect patients who remained in care and may differ from the original matched cohort.

DISCLOSURES:

The study was supported by the US Department of Veterans Affairs Cooperative Studies Program, US Department of Health and Human Services, Biomedical Advanced Research and Development Authority, and FDA. Two authors reported receiving grants from the study funder and/or the Patient-Centered Outcomes Research Institute; one of these authors also reported co-ownership of van Breemen & Hynes, LLC, unrelated to the submitted work.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.

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

TOPLINE:

A single dose of respiratory syncytial virus (RSV) vaccine provided protection against RSV illness and associated health care use in nearly 290,000 older US veterans over 2 respiratory illness seasons compared with unvaccinated individuals; however, protection declined over time, particularly among immunocompromised individuals.

METHODOLOGY:

• Researchers emulated a target trial to assess the long-term effectiveness of a single does of RSV vaccine, administered between September 2023 and March 2024, to prevent RSV infection and associated health care use among older US veterans.
• The primary outcome was any positive RSV test from 14 days after vaccination; secondary outcomes included RSV-associated emergency department or urgent care visits, hospitalizations, and ICU admissions.
• The median follow-up duration, measured from 14 days after vaccination, was 15.8 months, with a maximum of 19.0 months.

TAKEAWAY:

• The estimated vaccines effectiveness against RSV infection decreased from 82.5% (95% CI, 77.5%-86.9%) over 0 to 1 month to 59.4% (95% CI, 55.6%-63.5%) over 0 to 18 months of follow-up.
• Protection against RSV-associated emergency department and urgent care visits fell from 84.9% over 0 to 1 month to 60.6% over 0 to 18 months, and the estimated effectiveness against hospitalizations decreased from 88.9% to 57.3% over the same interval.
• The estimated effectiveness against RSV-associated ICU admissions reduced from 92.5% (95% CI, 61.1%-100%) over 0 to 1 month to 71.9% (95% CI, 42.8%-90.0%) over 0 to 18 months.
• Among immunocompromised individuals, protection against RSV infection showed the largest decline from 75.2% at 0 to 1 month to 39.7% over 18 months.

IN PRACTICE:

"Boosters may be needed, but for now, our efforts should be focused on saving lives and decreasing disease by encouraging vaccination of persons 75 years and older and those 60 years and older with underlying health issues," experts wrote in an accompanying editorial.

SOURCE:

The study was led by Kristina L. Bajema, MD, Veterans Affairs Portland Health Care System, Portland, Oregon. It was published online on November 24, 2025, in JAMA Internal Medicine.

LIMITATIONS:

RSV documentation may have been incomplete for veterans who sought care outside the Veterans Health Administration. The cohort was predominantly White men, limiting generalizability. Residual confounding could not be excluded. Estimates of long-term effectiveness should be interpreted cautiously because they reflect patients who remained in care and may differ from the original matched cohort.

DISCLOSURES:

The study was supported by the US Department of Veterans Affairs Cooperative Studies Program, US Department of Health and Human Services, Biomedical Advanced Research and Development Authority, and FDA. Two authors reported receiving grants from the study funder and/or the Patient-Centered Outcomes Research Institute; one of these authors also reported co-ownership of van Breemen & Hynes, LLC, unrelated to the submitted work.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.

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

TOPLINE:

A single dose of respiratory syncytial virus (RSV) vaccine provided protection against RSV illness and associated health care use in nearly 290,000 older US veterans over 2 respiratory illness seasons compared with unvaccinated individuals; however, protection declined over time, particularly among immunocompromised individuals.

METHODOLOGY:

• Researchers emulated a target trial to assess the long-term effectiveness of a single does of RSV vaccine, administered between September 2023 and March 2024, to prevent RSV infection and associated health care use among older US veterans.
• The primary outcome was any positive RSV test from 14 days after vaccination; secondary outcomes included RSV-associated emergency department or urgent care visits, hospitalizations, and ICU admissions.
• The median follow-up duration, measured from 14 days after vaccination, was 15.8 months, with a maximum of 19.0 months.

TAKEAWAY:

• The estimated vaccines effectiveness against RSV infection decreased from 82.5% (95% CI, 77.5%-86.9%) over 0 to 1 month to 59.4% (95% CI, 55.6%-63.5%) over 0 to 18 months of follow-up.
• Protection against RSV-associated emergency department and urgent care visits fell from 84.9% over 0 to 1 month to 60.6% over 0 to 18 months, and the estimated effectiveness against hospitalizations decreased from 88.9% to 57.3% over the same interval.
• The estimated effectiveness against RSV-associated ICU admissions reduced from 92.5% (95% CI, 61.1%-100%) over 0 to 1 month to 71.9% (95% CI, 42.8%-90.0%) over 0 to 18 months.
• Among immunocompromised individuals, protection against RSV infection showed the largest decline from 75.2% at 0 to 1 month to 39.7% over 18 months.

IN PRACTICE:

"Boosters may be needed, but for now, our efforts should be focused on saving lives and decreasing disease by encouraging vaccination of persons 75 years and older and those 60 years and older with underlying health issues," experts wrote in an accompanying editorial.

SOURCE:

The study was led by Kristina L. Bajema, MD, Veterans Affairs Portland Health Care System, Portland, Oregon. It was published online on November 24, 2025, in JAMA Internal Medicine.

LIMITATIONS:

RSV documentation may have been incomplete for veterans who sought care outside the Veterans Health Administration. The cohort was predominantly White men, limiting generalizability. Residual confounding could not be excluded. Estimates of long-term effectiveness should be interpreted cautiously because they reflect patients who remained in care and may differ from the original matched cohort.

DISCLOSURES:

The study was supported by the US Department of Veterans Affairs Cooperative Studies Program, US Department of Health and Human Services, Biomedical Advanced Research and Development Authority, and FDA. Two authors reported receiving grants from the study funder and/or the Patient-Centered Outcomes Research Institute; one of these authors also reported co-ownership of van Breemen & Hynes, LLC, unrelated to the submitted work.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.

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

Hi, everyone. I’m Dr Kenny Lin. I am a family physician and associate director of the Lancaster General Hospital Family Medicine Residency, and I blog at Common Sense Family Doctor.

The receding of the pandemic and the understandable desire to return to normalcy has made COVID-19 vaccines a lower priority for many of our patients. However, family physicians should keep in mind that from October 1, 2024, to September 6, 2025, COVID-19 was responsible for an estimated 3.2 to 4.6 million outpatient visits, 360,000 to 520,000 hospitalizations, and 42,000 to 60,000 deaths.

In a previous commentary, I discussed the worsening disconnect between the evidence supporting the effectiveness and safety of vaccinations and increasing reluctance of patients and parents to receive them, fueled by misinformation from federal health agencies and the packing of the Advisory Committee on Immunization Practices (ACIP) with vaccine skeptics. Since then, Secretary of Health and Human Services (HHS), Robert F. Kennedy, Jr, has fired Dr Susan Monarez, his handpicked director of the CDC. This caused three senior CDC officials to resign in protest and precipitated further turmoil at the embattled agency. 

The FDA has approved 3 updated COVID-19 vaccines targeted to currently circulating strains: an mRNA vaccine from Moderna (Spikevax) for those aged 6 months or older; an mRNA vaccine from Pfizer/BioNTech (Comirnaty) for those aged ≥ 5 years; and a protein subunit vaccine from Novavax (Nuvaxovid) for those aged ≥ 12 years. However, approvals restricting the scope of these approvals to certain high-risk groups, combined with the ACIP’s recent decision to not explicitly recommend them for any group, have complicated access for many patients.

Medical groups, including the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP), and the American College of Obstetricians and Gynecologists (ACOG), have published their own recommendations (Table). Of note, in opposition to the FDA and ACIP, the AAP and AAFP strongly recommend routine vaccination for children aged 6 to 23 months because they have the highest risk for hospitalization. The AAFP and ACOG both recommend COVID-19 vaccination in pregnancy to protect the pregnant patient and provide passive antibody protection to their infants up to 6 months of age. The Vaccine Integrity Project’s review of 12 safety studies published since June 2024 found that mRNA vaccines were not associated with increases in any adverse maternal or infant outcomes and had a possible protective effect against preterm birth.

In my previous commentary, 70% of Medscape readers indicated that they would follow vaccination recommendations from AAP even if they differed from CDC guidance. Administering vaccines outside of FDA labeling indications (i.e., “off label”) typically requires a physician’s prescription, which will almost certainly reduce COVID-19 vaccine uptake in children and pregnant patients, given that most people received these shots in pharmacies during the 2024-25 season. CVS and Walgreens, the country’s two largest pharmacy chains, are requiring physician prescriptions or waiting for ACIP guidance to make the new vaccines available in many states. However, an increasing number of states have implemented executive orders or passed legislation to permit pharmacists to provide vaccines to anyone who wants them. For example, the Pennsylvania State Board of Pharmacy voted unanimously to issue guidance that would allow pharmacists to administer any vaccines recommended by AAFP, AAP, or ACOG.

Erosion of vaccine uptake could easily worsen the burden of illness for our patients and the health system. Navigating the unnecessarily complex landscape of COVID-19 vaccines will be challenging, but it remains worthwhile.
 

Kenneth W. Lin, MD, MPH, Associate Director, Department of Family Medicine, Lancaster General Hospital, Lancaster, Pennsylvania, has disclosed the following relevant financial relationships: Serve(d) as a director, officer, partner, employee, advisor, consultant, or trustee for: UpToDate; American Academy of Family Physicians; Archdiocese of Washington; Association of Prevention Teaching and Research.

A version of this article appeared on Medscape.com.

Hi, everyone. I’m Dr Kenny Lin. I am a family physician and associate director of the Lancaster General Hospital Family Medicine Residency, and I blog at Common Sense Family Doctor.

The receding of the pandemic and the understandable desire to return to normalcy has made COVID-19 vaccines a lower priority for many of our patients. However, family physicians should keep in mind that from October 1, 2024, to September 6, 2025, COVID-19 was responsible for an estimated 3.2 to 4.6 million outpatient visits, 360,000 to 520,000 hospitalizations, and 42,000 to 60,000 deaths.

In a previous commentary, I discussed the worsening disconnect between the evidence supporting the effectiveness and safety of vaccinations and increasing reluctance of patients and parents to receive them, fueled by misinformation from federal health agencies and the packing of the Advisory Committee on Immunization Practices (ACIP) with vaccine skeptics. Since then, Secretary of Health and Human Services (HHS), Robert F. Kennedy, Jr, has fired Dr Susan Monarez, his handpicked director of the CDC. This caused three senior CDC officials to resign in protest and precipitated further turmoil at the embattled agency. 

The FDA has approved 3 updated COVID-19 vaccines targeted to currently circulating strains: an mRNA vaccine from Moderna (Spikevax) for those aged 6 months or older; an mRNA vaccine from Pfizer/BioNTech (Comirnaty) for those aged ≥ 5 years; and a protein subunit vaccine from Novavax (Nuvaxovid) for those aged ≥ 12 years. However, approvals restricting the scope of these approvals to certain high-risk groups, combined with the ACIP’s recent decision to not explicitly recommend them for any group, have complicated access for many patients.

Medical groups, including the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP), and the American College of Obstetricians and Gynecologists (ACOG), have published their own recommendations (Table). Of note, in opposition to the FDA and ACIP, the AAP and AAFP strongly recommend routine vaccination for children aged 6 to 23 months because they have the highest risk for hospitalization. The AAFP and ACOG both recommend COVID-19 vaccination in pregnancy to protect the pregnant patient and provide passive antibody protection to their infants up to 6 months of age. The Vaccine Integrity Project’s review of 12 safety studies published since June 2024 found that mRNA vaccines were not associated with increases in any adverse maternal or infant outcomes and had a possible protective effect against preterm birth.

In my previous commentary, 70% of Medscape readers indicated that they would follow vaccination recommendations from AAP even if they differed from CDC guidance. Administering vaccines outside of FDA labeling indications (i.e., “off label”) typically requires a physician’s prescription, which will almost certainly reduce COVID-19 vaccine uptake in children and pregnant patients, given that most people received these shots in pharmacies during the 2024-25 season. CVS and Walgreens, the country’s two largest pharmacy chains, are requiring physician prescriptions or waiting for ACIP guidance to make the new vaccines available in many states. However, an increasing number of states have implemented executive orders or passed legislation to permit pharmacists to provide vaccines to anyone who wants them. For example, the Pennsylvania State Board of Pharmacy voted unanimously to issue guidance that would allow pharmacists to administer any vaccines recommended by AAFP, AAP, or ACOG.

Erosion of vaccine uptake could easily worsen the burden of illness for our patients and the health system. Navigating the unnecessarily complex landscape of COVID-19 vaccines will be challenging, but it remains worthwhile.
 

Kenneth W. Lin, MD, MPH, Associate Director, Department of Family Medicine, Lancaster General Hospital, Lancaster, Pennsylvania, has disclosed the following relevant financial relationships: Serve(d) as a director, officer, partner, employee, advisor, consultant, or trustee for: UpToDate; American Academy of Family Physicians; Archdiocese of Washington; Association of Prevention Teaching and Research.

A version of this article appeared on Medscape.com.

Hi, everyone. I’m Dr Kenny Lin. I am a family physician and associate director of the Lancaster General Hospital Family Medicine Residency, and I blog at Common Sense Family Doctor.

The receding of the pandemic and the understandable desire to return to normalcy has made COVID-19 vaccines a lower priority for many of our patients. However, family physicians should keep in mind that from October 1, 2024, to September 6, 2025, COVID-19 was responsible for an estimated 3.2 to 4.6 million outpatient visits, 360,000 to 520,000 hospitalizations, and 42,000 to 60,000 deaths.

In a previous commentary, I discussed the worsening disconnect between the evidence supporting the effectiveness and safety of vaccinations and increasing reluctance of patients and parents to receive them, fueled by misinformation from federal health agencies and the packing of the Advisory Committee on Immunization Practices (ACIP) with vaccine skeptics. Since then, Secretary of Health and Human Services (HHS), Robert F. Kennedy, Jr, has fired Dr Susan Monarez, his handpicked director of the CDC. This caused three senior CDC officials to resign in protest and precipitated further turmoil at the embattled agency. 

The FDA has approved 3 updated COVID-19 vaccines targeted to currently circulating strains: an mRNA vaccine from Moderna (Spikevax) for those aged 6 months or older; an mRNA vaccine from Pfizer/BioNTech (Comirnaty) for those aged ≥ 5 years; and a protein subunit vaccine from Novavax (Nuvaxovid) for those aged ≥ 12 years. However, approvals restricting the scope of these approvals to certain high-risk groups, combined with the ACIP’s recent decision to not explicitly recommend them for any group, have complicated access for many patients.

Medical groups, including the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP), and the American College of Obstetricians and Gynecologists (ACOG), have published their own recommendations (Table). Of note, in opposition to the FDA and ACIP, the AAP and AAFP strongly recommend routine vaccination for children aged 6 to 23 months because they have the highest risk for hospitalization. The AAFP and ACOG both recommend COVID-19 vaccination in pregnancy to protect the pregnant patient and provide passive antibody protection to their infants up to 6 months of age. The Vaccine Integrity Project’s review of 12 safety studies published since June 2024 found that mRNA vaccines were not associated with increases in any adverse maternal or infant outcomes and had a possible protective effect against preterm birth.

In my previous commentary, 70% of Medscape readers indicated that they would follow vaccination recommendations from AAP even if they differed from CDC guidance. Administering vaccines outside of FDA labeling indications (i.e., “off label”) typically requires a physician’s prescription, which will almost certainly reduce COVID-19 vaccine uptake in children and pregnant patients, given that most people received these shots in pharmacies during the 2024-25 season. CVS and Walgreens, the country’s two largest pharmacy chains, are requiring physician prescriptions or waiting for ACIP guidance to make the new vaccines available in many states. However, an increasing number of states have implemented executive orders or passed legislation to permit pharmacists to provide vaccines to anyone who wants them. For example, the Pennsylvania State Board of Pharmacy voted unanimously to issue guidance that would allow pharmacists to administer any vaccines recommended by AAFP, AAP, or ACOG.

Erosion of vaccine uptake could easily worsen the burden of illness for our patients and the health system. Navigating the unnecessarily complex landscape of COVID-19 vaccines will be challenging, but it remains worthwhile.
 

Kenneth W. Lin, MD, MPH, Associate Director, Department of Family Medicine, Lancaster General Hospital, Lancaster, Pennsylvania, has disclosed the following relevant financial relationships: Serve(d) as a director, officer, partner, employee, advisor, consultant, or trustee for: UpToDate; American Academy of Family Physicians; Archdiocese of Washington; Association of Prevention Teaching and Research.

A version of this article appeared on Medscape.com.

(Reuters) -A top U.S. health official on Monday called for the combined measles-mumps-rubella shot to be broken up, drawing a quick rebuke from vaccine maker Merck, which said there is no scientific evidence that shows any benefit to doing so.

The U.S. CDC earlier on Monday pulled broad support for COVID-19 shots, saying they should be administered through shared decision-making with a health care provider in accordance with recommendations from Health Secretary Robert F. Kennedy Jr.’s hand-picked vaccine advisory panel.

The acting director of the Centers for Disease Control and Prevention, Jim O’Neill, in an X post on Monday called on vaccine manufacturers to develop three separate vaccines to replace the combined MMR inoculation.

In a September 23 news conference at the White House, President Donald Trump delivered medical advice to pregnant women and parents of young children, repeatedly telling them common vaccines should not be taken together or so early in a child’s life, and urging them not to use or administer Tylenol, against the advice of medical societies.

Kennedy, a long-time anti-vaccine crusader before taking on the nation’s top health post, has linked vaccines to autism and sought to rewrite the country’s immunization policies. He fired all members of the national vaccine advisory board of outside experts and replaced them with new members, many of whom shared his views. The committee is reviewing the childhood vaccine schedule.

The causes of autism are unclear. But no rigorous studies have found links between autism and vaccines or medications, or their components such as thimerosal or formaldehyde. Vaccination rates have declined as autism rates have climbed.

 

MERCK, EXPERTS DEFEND MMR SHOT

Merck said there is no published scientific evidence that shows any benefit in separating the MMR shot. 

According to the U.S. Food and Drug Administration’s website, there are currently no separate single virus shots for measles, mumps or rubella licensed for use in the United States. That means manufacturers could need to go through the FDA approval process before any become available.

“Use of the individual components of combination vaccines increases the number of injections for the individual and may result in delayed or missed immunizations,” Merck said in a statement.

Dr. Rana Alissa, president of the Florida chapter of the American Academy of Pediatrics, said the purpose of combining the three shots in the MMR vaccine is not only to save parents extra visits to the doctor’s office.

“Studies have shown that when you give them together, the immune response is much better,” she said. “This is how you get lifelong immunity.”

GSK, which also makes an MMR shot, declined to comment. A spokesman for the U.S. Department of Health and Human Services, where O’Neill is deputy secretary, was not immediately available for comment.

The break-up of the MMR shot would “falsely imply that there is something unsafe about giving the measles, mumps, and rubella vaccines at the same time,” said Dr. Amesh Adalja, an infectious disease expert at the Johns Hopkins Center for Health Security. 

“It would be another example of the federal government pandering to the anti-vaccine movement,” Adalja added.

Earlier in the day, the CDC signed off on the advisers’ recommendations against use of the combined measles-mumps-rubella-varicella vaccine before the age of 4 years because of a slight risk of seizures related to high fevers. Instead, varicella, commonly known as chickenpox, is recommended as a standalone shot.

Merck also makes the measles-mumps-rubella-varicella shot.

CDC CHANGES COVID VIEWS      

The new CDC recommendation on the COVID vaccine calls for physician involvement but maintains access for the shot through health insurance.

The immunization schedules will be updated on the CDC website by Tuesday, the agency said.

The recommendations come after upheaval at the CDC, including the ouster of its former Director Susan Monarez, who had resisted changes to vaccine policy advanced by Kennedy. Monarez said she was told to rubber-stamp the committee’s recommendations without reviewing the scientific evidence. 

The new advisory panel made its recommendations at a two-day meeting in September that highlighted deep divisions over the future of the U.S. immunization schedules under Kennedy.

The American Academy of Pediatrics, an influential U.S. medical group, has already broken from federal policy and pushed its own vaccine recommendations, suggesting all young children get vaccinated against COVID-19.

The U.S. Food and Drug Administration in August cleared updated COVID-19 vaccines for everyone over age 65, but limited its approval for younger people to those with health risks.

The 3 approved COVID shots are made by Pfizer with German partner BioNTech, Moderna, and Novavax with Sanofi.

(Reporting by Mariam Sunny in Bengaluru, Michael Erman in New York and Julie Steenhuysen in Chicago; Editing by Caroline Humer and Bill Berkrot)■

A version of this article appeared on Medscape.com.

(Reuters) -A top U.S. health official on Monday called for the combined measles-mumps-rubella shot to be broken up, drawing a quick rebuke from vaccine maker Merck, which said there is no scientific evidence that shows any benefit to doing so.

The U.S. CDC earlier on Monday pulled broad support for COVID-19 shots, saying they should be administered through shared decision-making with a health care provider in accordance with recommendations from Health Secretary Robert F. Kennedy Jr.’s hand-picked vaccine advisory panel.

The acting director of the Centers for Disease Control and Prevention, Jim O’Neill, in an X post on Monday called on vaccine manufacturers to develop three separate vaccines to replace the combined MMR inoculation.

In a September 23 news conference at the White House, President Donald Trump delivered medical advice to pregnant women and parents of young children, repeatedly telling them common vaccines should not be taken together or so early in a child’s life, and urging them not to use or administer Tylenol, against the advice of medical societies.

Kennedy, a long-time anti-vaccine crusader before taking on the nation’s top health post, has linked vaccines to autism and sought to rewrite the country’s immunization policies. He fired all members of the national vaccine advisory board of outside experts and replaced them with new members, many of whom shared his views. The committee is reviewing the childhood vaccine schedule.

The causes of autism are unclear. But no rigorous studies have found links between autism and vaccines or medications, or their components such as thimerosal or formaldehyde. Vaccination rates have declined as autism rates have climbed.

 

MERCK, EXPERTS DEFEND MMR SHOT

Merck said there is no published scientific evidence that shows any benefit in separating the MMR shot. 

According to the U.S. Food and Drug Administration’s website, there are currently no separate single virus shots for measles, mumps or rubella licensed for use in the United States. That means manufacturers could need to go through the FDA approval process before any become available.

“Use of the individual components of combination vaccines increases the number of injections for the individual and may result in delayed or missed immunizations,” Merck said in a statement.

Dr. Rana Alissa, president of the Florida chapter of the American Academy of Pediatrics, said the purpose of combining the three shots in the MMR vaccine is not only to save parents extra visits to the doctor’s office.

“Studies have shown that when you give them together, the immune response is much better,” she said. “This is how you get lifelong immunity.”

GSK, which also makes an MMR shot, declined to comment. A spokesman for the U.S. Department of Health and Human Services, where O’Neill is deputy secretary, was not immediately available for comment.

The break-up of the MMR shot would “falsely imply that there is something unsafe about giving the measles, mumps, and rubella vaccines at the same time,” said Dr. Amesh Adalja, an infectious disease expert at the Johns Hopkins Center for Health Security. 

“It would be another example of the federal government pandering to the anti-vaccine movement,” Adalja added.

Earlier in the day, the CDC signed off on the advisers’ recommendations against use of the combined measles-mumps-rubella-varicella vaccine before the age of 4 years because of a slight risk of seizures related to high fevers. Instead, varicella, commonly known as chickenpox, is recommended as a standalone shot.

Merck also makes the measles-mumps-rubella-varicella shot.

CDC CHANGES COVID VIEWS      

The new CDC recommendation on the COVID vaccine calls for physician involvement but maintains access for the shot through health insurance.

The immunization schedules will be updated on the CDC website by Tuesday, the agency said.

The recommendations come after upheaval at the CDC, including the ouster of its former Director Susan Monarez, who had resisted changes to vaccine policy advanced by Kennedy. Monarez said she was told to rubber-stamp the committee’s recommendations without reviewing the scientific evidence. 

The new advisory panel made its recommendations at a two-day meeting in September that highlighted deep divisions over the future of the U.S. immunization schedules under Kennedy.

The American Academy of Pediatrics, an influential U.S. medical group, has already broken from federal policy and pushed its own vaccine recommendations, suggesting all young children get vaccinated against COVID-19.

The U.S. Food and Drug Administration in August cleared updated COVID-19 vaccines for everyone over age 65, but limited its approval for younger people to those with health risks.

The 3 approved COVID shots are made by Pfizer with German partner BioNTech, Moderna, and Novavax with Sanofi.

(Reporting by Mariam Sunny in Bengaluru, Michael Erman in New York and Julie Steenhuysen in Chicago; Editing by Caroline Humer and Bill Berkrot)■

A version of this article appeared on Medscape.com.

(Reuters) -A top U.S. health official on Monday called for the combined measles-mumps-rubella shot to be broken up, drawing a quick rebuke from vaccine maker Merck, which said there is no scientific evidence that shows any benefit to doing so.

The U.S. CDC earlier on Monday pulled broad support for COVID-19 shots, saying they should be administered through shared decision-making with a health care provider in accordance with recommendations from Health Secretary Robert F. Kennedy Jr.’s hand-picked vaccine advisory panel.

The acting director of the Centers for Disease Control and Prevention, Jim O’Neill, in an X post on Monday called on vaccine manufacturers to develop three separate vaccines to replace the combined MMR inoculation.

In a September 23 news conference at the White House, President Donald Trump delivered medical advice to pregnant women and parents of young children, repeatedly telling them common vaccines should not be taken together or so early in a child’s life, and urging them not to use or administer Tylenol, against the advice of medical societies.

Kennedy, a long-time anti-vaccine crusader before taking on the nation’s top health post, has linked vaccines to autism and sought to rewrite the country’s immunization policies. He fired all members of the national vaccine advisory board of outside experts and replaced them with new members, many of whom shared his views. The committee is reviewing the childhood vaccine schedule.

The causes of autism are unclear. But no rigorous studies have found links between autism and vaccines or medications, or their components such as thimerosal or formaldehyde. Vaccination rates have declined as autism rates have climbed.

 

MERCK, EXPERTS DEFEND MMR SHOT

Merck said there is no published scientific evidence that shows any benefit in separating the MMR shot. 

According to the U.S. Food and Drug Administration’s website, there are currently no separate single virus shots for measles, mumps or rubella licensed for use in the United States. That means manufacturers could need to go through the FDA approval process before any become available.

“Use of the individual components of combination vaccines increases the number of injections for the individual and may result in delayed or missed immunizations,” Merck said in a statement.

Dr. Rana Alissa, president of the Florida chapter of the American Academy of Pediatrics, said the purpose of combining the three shots in the MMR vaccine is not only to save parents extra visits to the doctor’s office.

“Studies have shown that when you give them together, the immune response is much better,” she said. “This is how you get lifelong immunity.”

GSK, which also makes an MMR shot, declined to comment. A spokesman for the U.S. Department of Health and Human Services, where O’Neill is deputy secretary, was not immediately available for comment.

The break-up of the MMR shot would “falsely imply that there is something unsafe about giving the measles, mumps, and rubella vaccines at the same time,” said Dr. Amesh Adalja, an infectious disease expert at the Johns Hopkins Center for Health Security. 

“It would be another example of the federal government pandering to the anti-vaccine movement,” Adalja added.

Earlier in the day, the CDC signed off on the advisers’ recommendations against use of the combined measles-mumps-rubella-varicella vaccine before the age of 4 years because of a slight risk of seizures related to high fevers. Instead, varicella, commonly known as chickenpox, is recommended as a standalone shot.

Merck also makes the measles-mumps-rubella-varicella shot.

CDC CHANGES COVID VIEWS      

The new CDC recommendation on the COVID vaccine calls for physician involvement but maintains access for the shot through health insurance.

The immunization schedules will be updated on the CDC website by Tuesday, the agency said.

The recommendations come after upheaval at the CDC, including the ouster of its former Director Susan Monarez, who had resisted changes to vaccine policy advanced by Kennedy. Monarez said she was told to rubber-stamp the committee’s recommendations without reviewing the scientific evidence. 

The new advisory panel made its recommendations at a two-day meeting in September that highlighted deep divisions over the future of the U.S. immunization schedules under Kennedy.

The American Academy of Pediatrics, an influential U.S. medical group, has already broken from federal policy and pushed its own vaccine recommendations, suggesting all young children get vaccinated against COVID-19.

The U.S. Food and Drug Administration in August cleared updated COVID-19 vaccines for everyone over age 65, but limited its approval for younger people to those with health risks.

The 3 approved COVID shots are made by Pfizer with German partner BioNTech, Moderna, and Novavax with Sanofi.

(Reporting by Mariam Sunny in Bengaluru, Michael Erman in New York and Julie Steenhuysen in Chicago; Editing by Caroline Humer and Bill Berkrot)■

A version of this article appeared on Medscape.com.

TOPLINE: Human Papillomavirus (HPV) vaccination is associated with reduced risks of rheumatoid arthritis, systemic lupus erythematosus, and type 1 diabetes among females aged 9 to 45 years. The analysis of 208,638 vaccinated individuals shows particularly strong protective effects in those aged 9 to 26 years and recipients of 9-valent HPV vaccines.

METHODOLOGY:

• Researchers analyzed data from the US Collaborative Network in TriNetX spanning January 1, 2018, to December 20, 2022, enrolling 208,638 females aged 9 to 45 years who received HPV vaccination and matching them with 208,638 unvaccinated individuals using propensity scores.

• Analysis included Cox proportional hazard regression to estimate hazard ratios and 95% CIs for immune-mediated diseases, with subgroup analyses stratified by age, race, smoking, obesity, asthma, and HPV vaccine types.

• Participants were monitored from 31 days up to 365 days following their respective index dates, with sensitivity analyses conducted to evaluate short-term outcomes and compare results with influenza virus vaccine recipients.

TAKEAWAY:

• HPV vaccination demonstrated reduced risks for rheumatoid arthritis (hazard ratio [HR], 0.487; 95% confidence interval [CI], 0.311-0.762), systemic lupus erythematosus (HR, 0.287; 95% CI, 0.179-0.460), and dermatomyositis (HR, 0.299; 95% CI, 0.098-0.908).

• Recipients showed lower risks for inflammatory bowel disease (HR, 0.876; 95% CI, 0.811-0.946), celiac disease (HR, 0.400; 95% CI, 0.304-0.526), and type 1 diabetes (HR, 0.242; 95% CI, 0.184-0.318).

• Subgroup analyses revealed significant risk reductions among females aged 9 to 26 years and those receiving 9-valent HPV vaccines compared to unvaccinated populations.

• White and Black/African American individuals demonstrated reduced risks for various immune-mediated diseases, while Asians showed lower risks only for inflammatory bowel disease and overall immune-mediated diseases.

 IN PRACTICE: "Our real-world investigation employing TriNetX Research Network has revealed a significant reduction in the risks of various immune-mediated diseases, especially among females aged 9-26 years and those who received 9-valent HPV vaccines,” the author wrote.

SOURCE: The study was led by Qianru Zhang, MD, Beijing Tsinghua Changgung Hospital in Beijing, China, James Cheng-Chung Wei, and Shiow-Ing Wang who contributed equally as first authors. It was published online in QJM: An International Journal of Medicine.

LIMITATIONS:  According to the authors, research relying on Electronic Health Records (EHR) faced several constraints, including the absence of serial data on HPV antibody titers in vaccinated individuals and limited data regarding vaccination dosing numbers. Additionally, the current functionality of TriNetX prevented performing interaction terms in the statistical model for comprehensive subgroup analysis stratified by age, race, and vaccine types.

DISCLOSURES: The study received support from Chung Shan Medical University Hospital (Grant No. CSH-2023-E-001-Y2), Kaohsiung Veterans General Hospital (KSVGH 113-117), National Science and Technology Council (NSTC 112-2314-B-075B-020), and KSVNSU112-008. The funders had no role in the study's design, conduct, data analysis, or manuscript approval.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.

TOPLINE: Human Papillomavirus (HPV) vaccination is associated with reduced risks of rheumatoid arthritis, systemic lupus erythematosus, and type 1 diabetes among females aged 9 to 45 years. The analysis of 208,638 vaccinated individuals shows particularly strong protective effects in those aged 9 to 26 years and recipients of 9-valent HPV vaccines.

METHODOLOGY:

• Researchers analyzed data from the US Collaborative Network in TriNetX spanning January 1, 2018, to December 20, 2022, enrolling 208,638 females aged 9 to 45 years who received HPV vaccination and matching them with 208,638 unvaccinated individuals using propensity scores.

• Analysis included Cox proportional hazard regression to estimate hazard ratios and 95% CIs for immune-mediated diseases, with subgroup analyses stratified by age, race, smoking, obesity, asthma, and HPV vaccine types.

• Participants were monitored from 31 days up to 365 days following their respective index dates, with sensitivity analyses conducted to evaluate short-term outcomes and compare results with influenza virus vaccine recipients.

TAKEAWAY:

• HPV vaccination demonstrated reduced risks for rheumatoid arthritis (hazard ratio [HR], 0.487; 95% confidence interval [CI], 0.311-0.762), systemic lupus erythematosus (HR, 0.287; 95% CI, 0.179-0.460), and dermatomyositis (HR, 0.299; 95% CI, 0.098-0.908).

• Recipients showed lower risks for inflammatory bowel disease (HR, 0.876; 95% CI, 0.811-0.946), celiac disease (HR, 0.400; 95% CI, 0.304-0.526), and type 1 diabetes (HR, 0.242; 95% CI, 0.184-0.318).

• Subgroup analyses revealed significant risk reductions among females aged 9 to 26 years and those receiving 9-valent HPV vaccines compared to unvaccinated populations.

• White and Black/African American individuals demonstrated reduced risks for various immune-mediated diseases, while Asians showed lower risks only for inflammatory bowel disease and overall immune-mediated diseases.

 IN PRACTICE: "Our real-world investigation employing TriNetX Research Network has revealed a significant reduction in the risks of various immune-mediated diseases, especially among females aged 9-26 years and those who received 9-valent HPV vaccines,” the author wrote.

SOURCE: The study was led by Qianru Zhang, MD, Beijing Tsinghua Changgung Hospital in Beijing, China, James Cheng-Chung Wei, and Shiow-Ing Wang who contributed equally as first authors. It was published online in QJM: An International Journal of Medicine.

LIMITATIONS:  According to the authors, research relying on Electronic Health Records (EHR) faced several constraints, including the absence of serial data on HPV antibody titers in vaccinated individuals and limited data regarding vaccination dosing numbers. Additionally, the current functionality of TriNetX prevented performing interaction terms in the statistical model for comprehensive subgroup analysis stratified by age, race, and vaccine types.

DISCLOSURES: The study received support from Chung Shan Medical University Hospital (Grant No. CSH-2023-E-001-Y2), Kaohsiung Veterans General Hospital (KSVGH 113-117), National Science and Technology Council (NSTC 112-2314-B-075B-020), and KSVNSU112-008. The funders had no role in the study's design, conduct, data analysis, or manuscript approval.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.

TOPLINE: Human Papillomavirus (HPV) vaccination is associated with reduced risks of rheumatoid arthritis, systemic lupus erythematosus, and type 1 diabetes among females aged 9 to 45 years. The analysis of 208,638 vaccinated individuals shows particularly strong protective effects in those aged 9 to 26 years and recipients of 9-valent HPV vaccines.

METHODOLOGY:

• Researchers analyzed data from the US Collaborative Network in TriNetX spanning January 1, 2018, to December 20, 2022, enrolling 208,638 females aged 9 to 45 years who received HPV vaccination and matching them with 208,638 unvaccinated individuals using propensity scores.

• Analysis included Cox proportional hazard regression to estimate hazard ratios and 95% CIs for immune-mediated diseases, with subgroup analyses stratified by age, race, smoking, obesity, asthma, and HPV vaccine types.

• Participants were monitored from 31 days up to 365 days following their respective index dates, with sensitivity analyses conducted to evaluate short-term outcomes and compare results with influenza virus vaccine recipients.

TAKEAWAY:

• HPV vaccination demonstrated reduced risks for rheumatoid arthritis (hazard ratio [HR], 0.487; 95% confidence interval [CI], 0.311-0.762), systemic lupus erythematosus (HR, 0.287; 95% CI, 0.179-0.460), and dermatomyositis (HR, 0.299; 95% CI, 0.098-0.908).

• Recipients showed lower risks for inflammatory bowel disease (HR, 0.876; 95% CI, 0.811-0.946), celiac disease (HR, 0.400; 95% CI, 0.304-0.526), and type 1 diabetes (HR, 0.242; 95% CI, 0.184-0.318).

• Subgroup analyses revealed significant risk reductions among females aged 9 to 26 years and those receiving 9-valent HPV vaccines compared to unvaccinated populations.

• White and Black/African American individuals demonstrated reduced risks for various immune-mediated diseases, while Asians showed lower risks only for inflammatory bowel disease and overall immune-mediated diseases.

 IN PRACTICE: "Our real-world investigation employing TriNetX Research Network has revealed a significant reduction in the risks of various immune-mediated diseases, especially among females aged 9-26 years and those who received 9-valent HPV vaccines,” the author wrote.

SOURCE: The study was led by Qianru Zhang, MD, Beijing Tsinghua Changgung Hospital in Beijing, China, James Cheng-Chung Wei, and Shiow-Ing Wang who contributed equally as first authors. It was published online in QJM: An International Journal of Medicine.

LIMITATIONS:  According to the authors, research relying on Electronic Health Records (EHR) faced several constraints, including the absence of serial data on HPV antibody titers in vaccinated individuals and limited data regarding vaccination dosing numbers. Additionally, the current functionality of TriNetX prevented performing interaction terms in the statistical model for comprehensive subgroup analysis stratified by age, race, and vaccine types.

DISCLOSURES: The study received support from Chung Shan Medical University Hospital (Grant No. CSH-2023-E-001-Y2), Kaohsiung Veterans General Hospital (KSVGH 113-117), National Science and Technology Council (NSTC 112-2314-B-075B-020), and KSVNSU112-008. The funders had no role in the study's design, conduct, data analysis, or manuscript approval.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.

A mid-season analysis of the influenza vaccine by the US Department of Defensive (DoD) Global Respiratory Pathogen Surveillance Program (DoDGRPSP) has reported low to moderate vaccine effectiveness (VE). 

The study included 295 Military Health System (MHS) beneficiaries (adults and children) who tested positive for influenza and 965 controls who tested negative. Vaccinated patients had received the 2024-2025 influenza vaccine at least 14 days prior to symptom onset. The study conducted VE analyses for influenza A (any subtype), influenza A(H1N1)pdm09, and influenza A(H3N2). 

Overall, moderate effectiveness against influenza A(H1N1)pdm09 was reported in all beneficiaries and children aged 6 months to 17 years. In adults aged 18 to 64 years—and all beneficiaries—there was moderate effectiveness against influenza A(H3N2). VE estimates against influenza A (any subtype) for all beneficiaries, children, and adults were not significant; VE estimates were also not effective among children for influenza A(H3N2) and in adults for influenza A(H1N1)pdm09.

Adjusted VE estimates among all participants for influenza A (any subtypes), influenza A(H1N1)pdm09, and influenza A(H3N2) were 25%, 58%, and 42%, respectively. VE for influenza B was not calculated due to a low number of cases.

Flu vaccination rates for adults are usually in the 30% to 60% range despite the recommended target of 70%. Flu vaccination rates were rising by around 1% to 2% annually before 2020, but began dropping after the COVID-19 pandemic, especially in higher-risk groups. In adults aged ≥ 65 years, flu vaccination rates dropped from 52% in 2019-2020 to 43% in 2024-2025.

According to the Centers for Disease Control and Prevention (CDC), at the end of the 2023-2024 flu season, 9.2 million fewer doses were administered in pharmacies and doctors offices compared with the baseline before the COVID-19 pandemic. Since 2022, private manufacturers have distributed significantly fewer influenza vaccine doses. 

Each March, the US Food and Drug Association (FDA) Vaccines and Related Biological Products Advisory Committee (VRBPAC) meets to analyze the current influenza season and forecast the next. The committee reviews and discusses data on influenza strain circulation and VE, which come from DoDGRPSP analyses. In February, US Department of Health and Human Services officials indefinitely postponed a public meeting of the CDC Advisory Committee on Immunization Practice (ACIP), at which members were also expected to discuss, among other things, VE and vaccine recommendations. The FDA canceled a March 13 VRBPAC meeting and provided no reason for the cancelation to members. That day, however, the FDA issued new recommendations for the influenza vaccine for the 2025-2026 season without the input of VRBPAC. Instead, experts from the FDA, CDC, and DoD made recommendations after reviewing surveillance data from the US and globally.

For the 2025-2026 influenza season, the FDA recommends the vaccines be trivalent and target 2 strains of influenza A and 1 strain of influenza B. The FDA anticipates there will be an “adequate and diverse supply” of approved trivalent seasonal influenza vaccines. Trivalent flu vaccines are formulated to protect against 3 influenza viruses: an A(H1N1) virus, an A(H3N2) virus, and a B/Victoria virus. All influenza vaccines for the 2025-2026 season are anticipated to be trivalent in the US.

A mid-season analysis of the influenza vaccine by the US Department of Defensive (DoD) Global Respiratory Pathogen Surveillance Program (DoDGRPSP) has reported low to moderate vaccine effectiveness (VE). 

The study included 295 Military Health System (MHS) beneficiaries (adults and children) who tested positive for influenza and 965 controls who tested negative. Vaccinated patients had received the 2024-2025 influenza vaccine at least 14 days prior to symptom onset. The study conducted VE analyses for influenza A (any subtype), influenza A(H1N1)pdm09, and influenza A(H3N2). 

Overall, moderate effectiveness against influenza A(H1N1)pdm09 was reported in all beneficiaries and children aged 6 months to 17 years. In adults aged 18 to 64 years—and all beneficiaries—there was moderate effectiveness against influenza A(H3N2). VE estimates against influenza A (any subtype) for all beneficiaries, children, and adults were not significant; VE estimates were also not effective among children for influenza A(H3N2) and in adults for influenza A(H1N1)pdm09.

Adjusted VE estimates among all participants for influenza A (any subtypes), influenza A(H1N1)pdm09, and influenza A(H3N2) were 25%, 58%, and 42%, respectively. VE for influenza B was not calculated due to a low number of cases.

Flu vaccination rates for adults are usually in the 30% to 60% range despite the recommended target of 70%. Flu vaccination rates were rising by around 1% to 2% annually before 2020, but began dropping after the COVID-19 pandemic, especially in higher-risk groups. In adults aged ≥ 65 years, flu vaccination rates dropped from 52% in 2019-2020 to 43% in 2024-2025.

According to the Centers for Disease Control and Prevention (CDC), at the end of the 2023-2024 flu season, 9.2 million fewer doses were administered in pharmacies and doctors offices compared with the baseline before the COVID-19 pandemic. Since 2022, private manufacturers have distributed significantly fewer influenza vaccine doses. 

Each March, the US Food and Drug Association (FDA) Vaccines and Related Biological Products Advisory Committee (VRBPAC) meets to analyze the current influenza season and forecast the next. The committee reviews and discusses data on influenza strain circulation and VE, which come from DoDGRPSP analyses. In February, US Department of Health and Human Services officials indefinitely postponed a public meeting of the CDC Advisory Committee on Immunization Practice (ACIP), at which members were also expected to discuss, among other things, VE and vaccine recommendations. The FDA canceled a March 13 VRBPAC meeting and provided no reason for the cancelation to members. That day, however, the FDA issued new recommendations for the influenza vaccine for the 2025-2026 season without the input of VRBPAC. Instead, experts from the FDA, CDC, and DoD made recommendations after reviewing surveillance data from the US and globally.

For the 2025-2026 influenza season, the FDA recommends the vaccines be trivalent and target 2 strains of influenza A and 1 strain of influenza B. The FDA anticipates there will be an “adequate and diverse supply” of approved trivalent seasonal influenza vaccines. Trivalent flu vaccines are formulated to protect against 3 influenza viruses: an A(H1N1) virus, an A(H3N2) virus, and a B/Victoria virus. All influenza vaccines for the 2025-2026 season are anticipated to be trivalent in the US.

A mid-season analysis of the influenza vaccine by the US Department of Defensive (DoD) Global Respiratory Pathogen Surveillance Program (DoDGRPSP) has reported low to moderate vaccine effectiveness (VE). 

The study included 295 Military Health System (MHS) beneficiaries (adults and children) who tested positive for influenza and 965 controls who tested negative. Vaccinated patients had received the 2024-2025 influenza vaccine at least 14 days prior to symptom onset. The study conducted VE analyses for influenza A (any subtype), influenza A(H1N1)pdm09, and influenza A(H3N2). 

Overall, moderate effectiveness against influenza A(H1N1)pdm09 was reported in all beneficiaries and children aged 6 months to 17 years. In adults aged 18 to 64 years—and all beneficiaries—there was moderate effectiveness against influenza A(H3N2). VE estimates against influenza A (any subtype) for all beneficiaries, children, and adults were not significant; VE estimates were also not effective among children for influenza A(H3N2) and in adults for influenza A(H1N1)pdm09.

Adjusted VE estimates among all participants for influenza A (any subtypes), influenza A(H1N1)pdm09, and influenza A(H3N2) were 25%, 58%, and 42%, respectively. VE for influenza B was not calculated due to a low number of cases.

Flu vaccination rates for adults are usually in the 30% to 60% range despite the recommended target of 70%. Flu vaccination rates were rising by around 1% to 2% annually before 2020, but began dropping after the COVID-19 pandemic, especially in higher-risk groups. In adults aged ≥ 65 years, flu vaccination rates dropped from 52% in 2019-2020 to 43% in 2024-2025.

According to the Centers for Disease Control and Prevention (CDC), at the end of the 2023-2024 flu season, 9.2 million fewer doses were administered in pharmacies and doctors offices compared with the baseline before the COVID-19 pandemic. Since 2022, private manufacturers have distributed significantly fewer influenza vaccine doses. 

Each March, the US Food and Drug Association (FDA) Vaccines and Related Biological Products Advisory Committee (VRBPAC) meets to analyze the current influenza season and forecast the next. The committee reviews and discusses data on influenza strain circulation and VE, which come from DoDGRPSP analyses. In February, US Department of Health and Human Services officials indefinitely postponed a public meeting of the CDC Advisory Committee on Immunization Practice (ACIP), at which members were also expected to discuss, among other things, VE and vaccine recommendations. The FDA canceled a March 13 VRBPAC meeting and provided no reason for the cancelation to members. That day, however, the FDA issued new recommendations for the influenza vaccine for the 2025-2026 season without the input of VRBPAC. Instead, experts from the FDA, CDC, and DoD made recommendations after reviewing surveillance data from the US and globally.

For the 2025-2026 influenza season, the FDA recommends the vaccines be trivalent and target 2 strains of influenza A and 1 strain of influenza B. The FDA anticipates there will be an “adequate and diverse supply” of approved trivalent seasonal influenza vaccines. Trivalent flu vaccines are formulated to protect against 3 influenza viruses: an A(H1N1) virus, an A(H3N2) virus, and a B/Victoria virus. All influenza vaccines for the 2025-2026 season are anticipated to be trivalent in the US.