Moderna asks FDA to authorize vaccine for children younger than 6

Moderna said Thursday that it had asked the Food and Drug Administration to authorize its coronavirus vaccine for children younger than 6, making it the first manufacturer to do so. A top official said the firm would finish submitting data to regulators by May 9.

The development, which was expected, could intensify pressure on federal regulators to authorize a vaccine for the nation’s youngest children. Parents of the roughly 18 million youngest Americans, the only population group not yet eligible for vaccination, have been waiting for months for pediatric doses.

So far, Moderna’s vaccine has been cleared only for adults. The FDA has generally authorized COVID vaccines according to age group, calculating that the risks of severe disease and the benefits of vaccination are highest for the oldest Americans and reduced for young recipients. Moderna has also requested authorization of its COVID vaccine for 6- to 11-year-olds and 12to 17-year-olds, and a spokesperson said it would submit data rounding out those requests in about two weeks.

At a Senate oversight hearing Tuesday, Dr. Peter Marks, who oversees vaccine regulation for the FDA, hinted that the agency might consider Moderna’s applications for everyone younger than 18 as a whole. Some requests “are complicated because they are relatively larger, covering larger swaths of the pediatric population than others,” he said in response to a senator’s question about when a pediatric vaccine would be ready.

Moderna and Pfizer have both been developing doses for the youngest children since last year. Moderna is proposing a two-dose regimen for children from 6 months to 5 years old, using one-fourth the strength of an adult dose. Pfizer and Biontech are working on a three-dose regimen for those 6 months to 4 years old, at one-tenth the strength of the adult dose. Pfizer has not yet submitted a request for FDA authorization but is expected to do so soon.

Moderna’s clinical trial data showed that the antibody response of the youngest children compared favorably with that of adults ages 18-25, meeting the trial’s primary criterion for success. Although the trial was not big enough to measure vaccine effectiveness, Moderna said Thursday the vaccine appeared to be 51% effective against symptomatic infection among those younger than 2, and 37% effective among those 2-5.

Dr. Sean O’leary, an infectious disease specialist at Children’s Hospital Colorado, said, “There are a lot of parents who really desperately want a vaccine for a lot of good reasons. And we’re almost there.”

“I think these children need a vaccine,” he said. “On the other hand, I also recognize that it’s a complex situation” for the FDA.

O’leary also serves as vice chairman of the infectious disease committee of the American Academy of Pediatrics.