An expert committee advising the Food and Drug Administration on Tuesday recommended Moderna’s coronavirus vaccine for use in children and adolescents ages 6 to 17, an important step before emergency authorization.
The F.D.A. will likely follow the panel’s advice in the coming days, as it has consistently during the pandemic, and grant authorization. But doing so may have little immediate impact, since the age group has had access to Pfizer-BioNTech shots since last year.
On Wednesday, the committee is scheduled to vote on a more pressing question: whether to recommend emergency authorization of both the Moderna and Pfizer-BioNTech vaccines for the nation’s youngest children, who still are not eligible for any coronavirus shots.
The vote on the Moderna vaccine came at the end of an all-day meeting that focused in part on the medical and social consequences of Covid-19 for about 50 million children and teens. After the F.D.A. issues its decision, the Centers for Disease Control and Prevention would take up the matter, perhaps as early as Friday.
Dr. Katherine E. Fleming-Dutra, a medical officer at C.D.C., kicked off the meeting with a slew of data that she said showed that children and adolescents face notable risks of severe illness, even though the risks for adults are higher.
According to C.D.C. data as of June 7, there have been more than 10 million cases among ages 5 to 17, out of roughly 50 million children in the age group. That infection rate is likely a significant undercount because many cases go unreported.
As of last month, 189 children aged 5 to 11 and 443 adolescents and teens had died of Covid over the course of the pandemic, C.D.C. data shows. The surge from the Omicron variant over the winter led to the highest numbers of pediatric Covid cases, emergency department visits and hospitalization rates. Roughly two-thirds of children aged 6 to 17 who were hospitalized with Covid-19 had underlying conditions.
Dr. Fleming-Dutra also displayed charts showing the social impact of the virus. She said it 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. The pandemic has also led to mental health problems, less physical activity and fewer routine immunizations among children, she said.
Moderna first applied to cover 12 through 17 year olds a year ago. But federal health officials, concerned about possible links between the Moderna vaccine and a rare heart condition, myocarditis, chose to delay a decision. Moderna then held off on an application to cover 6- to 11-year-olds.
The company says concerns about myocarditis have now subsided after further research and real-world evidence. Federal health officials spent much of the morning presenting data to the advisory committee on the risks of that side effect.
Dr. Tom Shimabukuro, a vaccine safety official at the C.D.C., told the committee that some data on people ages 18 to 39 had suggested a higher risk of myocarditis among Moderna recipients compared to those who received the Pfizer-BioNTech 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.
Dr. Shimabukuro said the C.D.C. had confirmed 635 cases of myocarditis in children ages 5 to 17, out of almost 55 million doses of the Pfizer-BioNTech vaccine administered. The condition was concentrated in adolescent boys after receiving the second dose.
Based on health provider assessments, around 80 percent of those diagnosed appeared to have fully recovered, he said. Another 18 percent had improved but not fully recovered.
To evaluate how the vaccine works, Moderna studied immune responses generated in children 6 to 17 and compared them to the level of neutralizing antibodies in people 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. Company officials said they planned to examine real-world effectiveness if the shots are authorized, and will soon submit clinical trial data on how booster shots work.
The F.D.A. found that the vaccine met the criteria for success with the antibodies it induced, but cautioned that a third dose would likely be necessary for children and teens, just as it has been for adults, 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, Dr. Doran Fink, a senior F.D.A. regulator, said. The F.D.A. has authorized a booster shot for all Pfizer recipients, aged 5 and older, and the C.D.C. recommended the additional doses.
Dr. Paul Offit, a vaccine expert with the Children’s Hospital of Philadelphia, said he was voting to recommend the vaccine on the assumption that a third dose would be authorized.
The virus is evolving so fast that “you’re always going to be behind the 8-ball,” Dr. Eric Rubin, another panel member and an adjunct professor of immunology at the Harvard T.H. Chan School of Public Health, said. “I don’t think we want to pass up the opportunity to offer something.”
The F.D.A.’s assessment that the vaccine met the immune response criteria, combined with its conclusion that side effects in the age group are minimal, suggested that federal regulators will likely authorize it.
A separate committee that advises the C.D.C. is expected to take up the matter this weekend, after which Dr. Rochelle P. Walensky, the agency’s director, will issue her own recommendation. Children could begin receiving the shots soon after Dr. Walensky’s approval.
In a second all-day meeting on Wednesday, the F.D.A. panel will consider Moderna’s vaccine for children under 6 and Pfizer-BioNTech’s vaccine for children under 5. About 18 million children 4 and younger are the only Americans not yet cleared for coronavirus shots.
Whether there will be any real demand for Moderna’s vaccine among teens and older children, given that the Pfizer-BioNTech vaccine has already been available to them for months, is a question likely to surface at Tuesday’s meeting. Uptake of the Pfizer vaccine, which uses the same technology, has been halting among 5- to 11-year-olds. Just over a third of the 28 million children in the age group have received at least one dose, compared to nearly 70 percent of those aged 12 to 17.
Jason L. Schwartz, a vaccine policy expert at the Yale School of Public Health, said the authorization of Moderna’s vaccine for children aged 6 to 17 would be useful even if relatively few of them get it.
The Moderna option, he said, would be like an “insurance policy” in case manufacturing problems or new safety concerns arise with Pfizer’s vaccine. Pediatricians and primary care physicians, he said, may choose to stock their offices with both products.
Dr. Schwartz said the Moderna authorization could also prove to be 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.”