Update June 17, 2022: The FDA has authorized Moderna vaccines for children and adolescents ages 6 months through 17 years. The CDC will now discuss whether to recommend their use for these ages. For the latest news on COVID-19, visit http://bit.ly/AAPNewsCOVID19.
A federal vaccine panel is recommending authorization of Moderna’s COVID-19 vaccine for children and adolescents ages 6-17 years.
The Food and Drug Administration’s (FDA’s) Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted 22-0, saying the benefits outweigh the risks. The recommendation will go to the FDA commissioner and then the Centers for Disease Control and Prevention (CDC) for consideration.
“I believe the vote, and I’m happy to see it was unanimous, is standing up for vulnerable populations that merit consideration in terms of protection against this virus,” said VRBPAC member Ofer Levy, M.D., Ph.D., director of the Precision Vaccines Program at Boston Children’s Hospital. “I believe that this will provide families an important option.”
The Moderna vaccine for adolescents ages 12-17 is the same dose as for adults — 100 micrograms (µg), given as two doses 28 days apart. Children ages 6-11 years would get two 50-µg doses.
While the vaccine would be new for U.S. children and adolescents, it is being used widely in other countries. More than 6.4 million adolescents and 300,000 children ages 6-11 have been fully vaccinated with it worldwide.
Pfizer-BioNTech COVID-19 vaccines were approved for children ages 5-17 years last year, but uptake has stalled. About 60% of adolescents and 29% of children ages 5-11 are fully vaccinated, according to CDC data.
Clinical trials evaluating safety included more than 2,000 adolescents and more than 3,000 children. For both groups, the most common systemic reactions to the Moderna vaccine were headache and fatigue. Most reactions were mild to moderate. There were no serious adverse events related to the vaccine except one case of ileus in a child with a complex medical history, which the FDA said is "possibly related” to the vaccine. About 5% of adolescents and 2% of children experienced lymphadenopathy-related events.
There were no cases of myocarditis or pericarditis after vaccination in the trials. The condition is rare but does occur above baseline rates for some age groups. Adolescent and young adult males have had the highest rates with the Pfizer-BioNTech vaccine, which is an mRNA vaccine like Moderna’s. There have been 635 confirmed cases among vaccine recipients ages 5-17 reported through the Vaccine Adverse Events Reporting System out of nearly 55 million doses administered to that age group. FDA officials said they do not believe myocarditis/pericarditis risks are higher with Moderna than the Pfizer-BioNTech vaccine.
“I think we need to do whatever we can to allay parental concerns regarding myocarditis because I do think that’s a major concern for the public,” said VRBPAC member Henry H. Bernstein, D.O., M.H.C.M., FAAP, professor of pediatrics at the Zucker School of Medicine at Hofstra/Northwell Health.
Myocarditis is more common and typically more severe after COVID-19 infection than after vaccination. Tom Shimabukuro, M.D., M.P.H., M.B.A., from the CDC’s COVID-19 Vaccine Coordination Unit, said, “CDC and FDA are conducting the most rigorous monitoring in the history of vaccine safety for these COVID vaccines.”
Immunogenicity and efficacy
Among adolescents, the geometric mean titer (GMT) ratio after Moderna’s vaccine was 1.1 compared to trials in young adults, meeting FDA criteria. Vaccine effectiveness for adolescents was 93.3% against symptomatic infection.
In children, the GMT ratio compared to young adults was 1.2, again meeting FDA criteria. Vaccine effectiveness against symptomatic infection was 76.8%, according to an FDA analysis. However, confidence intervals were wide, and the FDA said efficacy was difficult to calculate due to the availability of the Pfizer-BioNTech vaccine for this age group.
The trials were conducted before the emergence of the omicron variant, leaving questions about how well it would perform now. Several VRBPAC members said they expect a third dose to be needed. The Pfizer-BioNTech vaccine has a two-dose primary series and a recommended booster dose for children and adolescents.
“The question is, will two doses of this vaccine offer adequate protection against omicron subvariants? I think the answer certainly regarding mild illness, no,” said VRBPAC member Paul Offit, M.D., FAAP, director of the Vaccine Education Center at Children’s Hospital of Philadelphia. “And I think regarding severe illness yes as long as there’s a third dose.”
VRBPAC member Eric J. Rubin, M.D., Ph.D., adjunct professor of immunology and infectious diseases at the Harvard T.H. Chan School of Public Health agreed a third dose probably would be necessary but said the group has to work with the available data.
“We’re always going to be looking at the last variant or the variant before that because of how long it takes to produce these data,” Dr. Rubin said. “And I think we have to make decisions based on the best data we have, which is going to be old … in an outbreak that is constantly moving. … I think the ability to protect against severe disease is quite compelling, so I don’t think we want to pass up the opportunity to offer something to these kids.”
COVID in children
VRBPAC’s recommendation for a second vaccine for children and adolescents comes as there have been nearly 10.7 million COVID-19 cases in those ages 5-17 years. Seroprevalence data indicate that figure likely is even higher due to cases being undiagnosed or unreported. At least 433 adolescents and 189 children ages 5-11 years have died of COVID-19.
VRBPAC will meet again Wednesday to discuss a Moderna COVID-19 vaccine for children under 6 years and a Pfizer-BioNTech vaccine for children under 5 years. The CDC’s Advisory Committee on Immunization Practices will meet Friday and Saturday to discuss pediatric COVID vaccines.