ID Consult

COVID-19 vaccinations lag in youngest children


Case: A 3-year-old girl presented to the emergency department after a brief seizure at home. She looked well on physical exam except for a fever of 103° F and thick rhinorrhea.

The intern on duty methodically worked through the standard list of questions. “Immunizations up to date?” she asked.

“Absolutely,” the child’s mom responded. “She’s had everything that’s recommended.”

“Including COVID-19 vaccine?” the intern prompted.

Dr. Kristina A. Bryant president of the Pediatric Infectious Diseases Society, is a pediatrician at the University of Louisville (Ky.) and Norton Children’s Hospital, also in Louisville.

Dr. Kristina A. Bryant

“No.” The mom responded with a shake of her head. “We don’t do that vaccine.”

That mom is not alone.

COVID-19 vaccines for children as young as 6 months were given emergency-use authorization by the Food and Drug Administration in June 2022 and in February 2023, the Advisory Committee on Immunization Practices included COVID-19 vaccine on the routine childhood immunization schedule.

COVID-19 vaccines are safe in young children, and they prevent the most severe outcomes associated with infection, including hospitalization. Newly released data confirm that the COVID-19 vaccines produced by Moderna and Pfizer also provide protection against symptomatic infection for at least 4 months after completion of the monovalent primary series.

In a Morbidity and Mortality Weekly Report released on Feb. 17, 2023, the Centers for Disease Control and Prevention reported the results of a test-negative design case-control study that enrolled symptomatic children tested for SARS-CoV-2 infection through Feb. 5, 2023, as part of the Increasing Community Access to Testing (ICATT) program.1 ICATT provides SARS-CoV-2 testing to persons aged at least 3 years at pharmacy and community-based testing sites nationwide.

Two doses of monovalent Moderna vaccine (complete primary series) was 60% effective against symptomatic infection (95% confidence interval, 49%-68%) 2 weeks to 2 months after receipt of the second dose. Vaccine effectiveness dropped to 36% (95% CI, 15%-52%) 3-4 months after the second dose. Three doses of monovalent Pfizer-BioNTech vaccine (complete primary series) was 31% effective (95% CI, 7%-49%) at preventing symptomatic infection 2 weeks to 4 months after receipt of the third dose. A bivalent vaccine dose for eligible children is expected to provide more protection against currently circulating SARS-CoV-2 variants.

Kymber Ezell, BA

Despite evidence of vaccine efficacy, very few parents are opting to protect their young children with the COVID-19 vaccine. The CDC reports that, as of March 1, 2023, only 8% of children under 2 years and 10.5% of children aged 2-4 years have initiated a COVID vaccine series. The American Academy of Pediatrics has emphasized that 15.0 million children between the ages of 6 months and 4 years have not yet received their first COVID-19 vaccine dose.

While the reasons underlying low COVID-19 vaccination rates in young children are complex, themes emerge. Socioeconomic disparities contributing to low vaccination rates in young children were highlighted in another recent MMWR article.2 Through Dec. 1, 2022, vaccination coverage was lower in rural counties (3.4%) than in urban counties (10.5%). Rates were lower in Black and Hispanic children than in White and Asian children.

According to the CDC, high rates of poverty in Black and Hispanic communities may affect vaccination coverage by affecting caregivers’ access to vaccination sites or ability to leave work to take their child to be vaccinated. Pediatric care providers have repeatedly been identified by parents as a source of trusted vaccine information and a strong provider recommendation is associated with vaccination, but not all families are receiving vaccine advice. In a 2022 Kaiser Family Foundation survey, parents of young children with annual household incomes above $90,000 were more likely to talk to their pediatrician about a COVID-19 vaccine than families with lower incomes.3Vaccine hesitancy, fueled by general confusion and skepticism, is another factor contributing to low vaccination rates. Admittedly, the recommendations are complex and on March 14, 2023, the FDA again revised the emergency-use authorization for young children. Some caregivers continue to express concerns about vaccine side effects as well as the belief that the vaccine won’t prevent their child from getting sick.

Kendall Purcell, MD, a pediatrician with Norton Children’s Medical Group in Louisville, Ky., recommends COVID-19 vaccination for her patients because it reduces the risk of severe disease. That factored into her own decision to vaccinate her 4-year-old son and 1-year-old daughter, but she hasn’t been able to convince the parents of all her patients. “Some feel that COVID-19 is not as severe for children, so the risks don’t outweigh the benefits when it comes to vaccinating their children.” Back to our case: In the ED the intern reviewed the laboratory testing she had ordered. She then sat down with the mother of the 3-year-old girl to discuss the diagnosis: febrile seizure associated with COVID-19 infection. Febrile seizures are a well-recognized but uncommon complication of COVID-19 in children. In a retrospective cohort study using electronic health record data, febrile seizures occurred in 0.5% of 8,854 children aged 0-5 years with COVID-19 infection.4 About 9% of these children required critical care services. In another cohort of hospitalized children, neurologic complications occurred in 7% of children hospitalized with COVID-19.5 Febrile and nonfebrile seizures were most commonly observed.

“I really thought COVID-19 was no big deal in young kids,” the mom said. “Parents need the facts.”

The facts are these: Through Dec. 2, 2022, more than 3 million cases of COVID-19 have been reported in children aged younger than 5 years. While COVID is generally less severe in young children than older adults, it is difficult to predict which children will become seriously ill. When children are hospitalized, one in four requires intensive care. COVID-19 is now a vaccine-preventable disease, but too many children remain unprotected.

Dr. Bryant is a pediatrician specializing in infectious diseases at the University of Louisville (Ky.) and Norton Children’s Hospital, also in Louisville. She is a member of the AAP’s Committee on Infectious Diseases and one of the lead authors of the AAP’s Recommendations for Prevention and Control of Influenza in Children, 2022-2023. The opinions expressed in this article are her own. Dr. Bryant discloses that she has served as an investigator on clinical trials funded by Pfizer, Enanta, and Gilead. Email her at Ms. Ezell is a recent graduate from Indiana University Southeast with a Bachelor of Arts in English. They have no conflicts of interest.


1. Fleming-Dutra KE et al. Morb Mortal Wkly Rep. 2023;72:177-182.

2. Murthy BP et al. Morb Mortal Wkly Rep. 2023;72:183-9.

3. Lopes L et al. KFF COVID-19 vaccine monitor: July 2022. San Francisco: Kaiser Family Foundation, 2022.

4. Cadet K et al. J Child Neurol. 2022 Apr;37(5):410-5.

5. Antoon JW et al. Pediatrics. 2022 Nov 1;150(5):e2022058167.

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