Expert Panel Recommends Authorization of Pfizer’s COVID-19 Vaccine for Kids Aged 5-11

Pfizer/BioNtech’s Emergency Use Authorization (EUA) application for a COVID-19 vaccine for young children has cleared its first regulatory hurdle.

With 17 votes of support and one abstention, the FDA’s Vaccines and Related Biological Products Advisory Committee yesterday voted that two doses of 10 micrograms three weeks apart showed a positive risk/benefit profile in children aged five to 11 years old. The recommendation to expand Pfizer/BioNtech’s EUA to this age group must now be approved by the FDA. Then the application will go before a Centers for Disease Control and Prevention expert panel on vaccine practices, which is scheduled to meet next week.

While ultimately supporting the vaccine for young children, members of the FDA’s advisory committee wrestled with several tough issues, among them, the potential for induced myocarditis, a known side effect of the higher-dose vaccine, especially among older boys and men. But, several members pointed out, the rates of myocarditis presented in six risk-benefit scenarios were extrapolated to young children and probably overestimate the actual risk.

Nevertheless, much about the vaccine remains an unknown in this population — something that gave members pause, even as they acknowledged its potential benefit, especially for children in high-risk groups. And they worried that their support might set the stage for state-mandated vaccination  for school attendance. This was a real concern for most committee members, who could vote only yes or no on whether to recommend the vaccine for young kids and could not offer any conditional recommendations.

A few members also pointed out that the vaccine will likely benefit only a small percentage of healthy children. New data find that upward of 40 percent of those in this age group already have natural antibodies, and that 68 percent of those hospitalized with COVID-19 have underlying medical conditions.

Preventing disease is one part of the risk-benefit equation but it’s harder to measure the societal risks children face when they can’t go to school, learn in open environments and associate with peers, said Hayley Gans, Stanford University Medical Center. And since 12 states now have laws on the books forbidding mask mandates in schools, something else must be done to stem disease transmission, she said.

The data on long-term immunity are not yet clear, according to the presentation by Pfizer. But based on adult data, committee members appeared to think annual boosters will be necessary for children.

Much of the panel’s discussion revolved around the agency’s risk/benefit analysis, which compared rates of vaccine-associated myocarditis to rates of COVID-19 infections, hospitalizations, ICU admissions and deaths in six different epidemiologic scenarios.

Pfizer’s recent data suggest the vaccine is almost 91 percent effective against symptomatic COVID-19  (DID, Oct. 25).

With this efficacy and a COVID-19 incidence similar to that seen in mid-September, the vaccine would prevent almost 59,000 cases, 241 hospitalizations, 77 ICU stays and one death, while causing 106 myocarditis cases, 92 hospitalizations and 34 ICU stays.

The vaccine looked riskier in an analysis that assumed very low COVID-19 incidence. Here, it prevented 2,639 infections, hospitalizations and seven ICU stays, but caused 106 myocarditis cases, 92 hospitalizations and 34 ICU stays.

“Here we see much less benefit,” said Hong Yang of the FDA’s Center for Biologic Evaluation and Research. “But we must also consider the implications of hospital and ICU stays” associated with each scenario. COVID stays typically require much more intensive management compared to relatively mild management in myocarditis admissions. “We also must factor in the benefit of preventing postCOVID morbidity, and when we do this, the overall benefit still outweighs the risk.” — Michele G. Sullivan