An expert committee advising the Food and Drug Administration on Tuesday unanimously recommended Moderna’s coronavirus vaccine for use in children and adolescents ages 6 to 17, an important step before emergency authorization.
The FDA will likely follow the panel’s advice in the coming days, as it has done consistently during the pandemic, and grant authorization. But doing so may have little immediate effect, since the age group has had access to Pfizer-BioNTech shots since last year. To date, Moderna’s shots have been authorized only for adults.
On Wednesday, the committee is scheduled to vote on a more pressing question: whether to recommend emergency authorization of both the Moderna and Pfizer vaccines for the nation’s youngest children, who are still not eligible for any coronavirus shots. Both the FDA and the Centers for Disease Control and Prevention will prioritize decisions on that matter over Moderna shots for older children and teens because of the unmet need, officials familiar with the planning said.
The votes on the Moderna vaccine came at the end of a daylong meeting that focused in part on the medical and social consequences of COVID-19 for about 50 million children and teens.
Moderna first applied to cover 12- through 17-year-olds a year ago, with two doses at the same level as adults. But federal health officials, concerned about possible links between the Moderna vaccine and a rare heart condition, myocarditis, delayed a decision. Moderna then held off on an application to cover 6- to 11-year-olds, who would receive two doses at half the strength of adult levels.
The company now says concerns about myocarditis have subsided after further research and real-world evidence. Federal health officials repeatedly addressed the risks of that side effect in the panel’s sessions.
To evaluate how the vaccine works, Moderna studied immune responses generated in children 6 to 17 and compared them with the level of neutralizing antibodies in people ages 18 to 25 after vaccination. Because of the small number of virus cases among trial participants, Moderna’s efficacy data fell far short of the data collected for adults.
Experts warned against comparing Moderna’s vaccine with Pfizer’s for elementary, middle and high schoolers, even though the vaccines have largely followed parallel tracks. Among other differences, data was collected during different periods, with different dosages.
While the FDA found that Moderna’s vaccine met the criteria for success with the antibodies it induced, regulators cautioned that a third dose would likely be necessary for children and teens, just as it has been for adults, in order to counter waning of the vaccine’s potency against infection over time.
“We would anticipate taking the same course with this vaccine” as the agency has done with Pfizer’s, Dr. Doran Fink, a senior FDA regulator, said. Studies showed that the omicron variant severely diminished the power of two doses of Pfizer’s shot in children, prompting federal regulators to clear a third dose for those as young as 5 in May.
Moderna officials told the committee they planned to submit clinical trial data on booster shots for children soon and examine real-world evidence if the shots are authorized.
Dr. Katherine E. Fleming-Dutra, a medical officer at the CDC, kicked off the meeting with an abundance of data that she said showed children and adolescents faced notable risks of severe illness from COVID, even though the risks for adults were higher.
According to CDC data as of June 7, there have been more than 10 million cases among children ages 5 to 17, out of roughly 50 million children in the age group. That is likely a significant undercount because many cases go unreported.
As of last month, 189 children ages 5 to 11 and 443 adolescents and teens had died of COVID-19, CDC data shows. The surge from the omicron variant over the winter led to the highest number of pediatric COVID cases, emergency department visits and hospitalization rates. Roughly two-thirds of children ages 6 to 17 who were hospitalized with COVID-19 had existing health conditions.
Fleming-Dutra also said the virus had caused thousands of school disruptions each week during the omicron wave, worsening education gaps. Many parents, especially those with lower incomes, left jobs or changed work schedules to look after children, she said.
Dr. Tom Shimabukuro, a vaccine safety official at the CDC, told the committee that some data on people ages 18-39 had suggested a higher risk of myocarditis in Moderna recipients compared with those who got the Pfizer vaccine. Moderna’s dosage is substantially higher than Pfizer’s.
But he cautioned that the evidence was not consistent across U.S. monitoring systems. And he stressed that myocarditis, which can also be caused by the virus itself, was a rare side effect.
Shimabukuro said the CDC had confirmed 635 cases of myocarditis in children ages 5-17, out of almost 55 million doses of the Pfizer vaccine administered. The condition was concentrated in adolescent boys after they had received the second dose.
Based on health provider assessments, around 80% of those diagnosed appeared to have fully recovered, he said. A further 18% had improved but not fully recovered.
Dr. Paul Offit, a vaccine expert with the Children’s Hospital of Philadelphia and an advisory committee member, said he was voting to recommend the vaccine on the assumption that a third dose would eventually be authorized to help counter the variants and subvariants now circulating. “We’re not in the same part of the pandemic anymore,” he said.
Other panel members emphasized that clearing two doses was a necessary first step.
The virus is evolving so fast that “you’re always going to be behind the eight ball,” said Dr. Eric Rubin, another panel member and an adjunct professor of immunology at the Harvard T.H. Chan School of Public Health. “I don’t think we want to pass up the opportunity to offer something.”
The FDA’s assessment that the vaccine met the immune response criteria, combined with its conclusion that side effects in the age group were minimal, also suggests that federal regulators will likely authorize it.
A separate committee that advises the CDC is expected to take up the matter next week, after which Dr. Rochelle Walensky, the agency’s director, will issue her own recommendation. Children could begin receiving the shots soon after Walensky’s approval.
In a second all-day meeting Wednesday, the FDA panel will consider Moderna’s vaccine for children younger than 6 and Pfizer-BioNTech’s vaccine for children younger than 5. About 20 million children 4 and younger are the only Americans not yet cleared for shots.
Uptake of the Pfizer vaccine, which uses the same technology as Moderna’s, has been halting among 5- to 11-year-olds. Just over one-third of the 28 million children in the age group have received at least one dose, compared with nearly 70% of those ages 12-17.
Jason L. Schwartz, a vaccine policy expert at the Yale School of Public Health, said the authorization of Moderna’s vaccine for children ages 6-17 would be useful even if relatively few got it.
The Moderna option, he said, would be like an “insurance policy” in case manufacturing problems or new safety concerns arose with Pfizer’s vaccine.
Schwartz also said the Moderna authorization could prove valuable in the long term.
“We’re still learning how these vaccines perform, both about levels and duration of protection,” he said. “We may learn over time that one vaccine is better.”
This article originally appeared in The New York Times.