FDA advisers vote to recommend Moderna Covid vaccine EUA for kids 6-17

The FDA’s independent vaccine advisers unanimously voted Tuesday to recommend the agency authorize Moderna’s Covid-19 vaccine for teens and for children as young as 6, increasing the likelihood of a second product being available to immunize the age group.

The 22-0 votes came after a daylong meeting in which panel members largely agreed that the benefits of having another vaccine available to these age groups outweigh the potential risks. Both age groups — 12- to 17-year-olds and 6- to 11-year-olds — have had access to the Pfizer-BioNTech vaccine since May 2021 and November 2021, respectively.

The FDA said in a briefing document published Friday that its analysis of Moderna’s data confirmed the shot was generally safe and effective in the two age groups. Teens would receive a 100-microgram dose per shot — same as adults — while younger children would receive 50-microgram doses, all one month apart.

Efficacy of Moderna's vaccine ranged from about 77 percent for kids 6 to 11 to 93 percent for 12- to 17-year-olds. But those studies were conducted when the Delta variant and the Alpha strain, respectively, were predominant, raising questions about how effective the two-dose primary series is against Omicron.

Committee members urged federal health officials to communicate the benefits of an eventual third dose — which is not yet being considered for those age groups with respect to Moderna's shot — in protecting recipients from the worst effects of Omicron and its subvariants.

The advisory committee will consider Moderna’s vaccine for children ages 6 months through 5 years, which would be a 25-microgram dose, on Wednesday alongside Pfizer-BioNTech’s bid to vaccinate kids under 5.

The FDA is not required to follow its advisory committees' recommendations, but it usually does. Should FDA authorize the shots this week, the Centers for Disease Control and Prevention's independent advisory panel likely will consider endorsing their administration during meetings on Friday and Saturday.

It’s unclear whether making Moderna’s vaccine available to teens and younger kids will do much to change the trajectory of adolescent and child vaccination against Covid.

Just 29 percent of U.S. children ages 5 to 11 are fully vaccinated against Covid, compared to nearly 56 percent of 12- to 15-year-olds and 67 percent of 16- and 17-year-olds, according to CDC data ending April 30.

Asked how the product could help improve vaccine uptake, Rituparna Das, Moderna's vice president for clinical development, said the company is reaching out to pediatricians and other vaccine administrators to answer questions.

“I think the goal would be for all of us together to increase vaccine uptake, but I can’t speculate on what the authorization specifically would do," she said.

Recent polling by the Kaiser Family Foundation suggests about 20 percent of parents are eager to vaccinate their children under 5 as soon as they’re allowed to, while nearly 40 percent plan to “wait and see” how the vaccine works in other kids and another 40 percent are more reluctant to immunize at all.

No cases of myocarditis or pericarditis — inflammation of the heart muscle or lining, respectively — were reported in Moderna's pediatric trials. Both conditions are known risks of Covid-19 messenger RNA vaccines, particularly among males ages 12 to 39.

Data from international vaccine safety surveillance programs have suggested that a higher rate of the heart conditions occurs after immunization with Moderna's shots than with Pfizer-BioNTech's. That information, along with the availability of the Pfizer vaccine for adolescents, convinced the FDA last fall not to move forward with an EUA then for 12- to 17-year-olds, the agency said in the briefing document.

But analyses of U.S. data in active and passive surveillance systems conducted in April and May "do not support a difference in myocarditis/pericarditis risk for [Moderna] as compared to [Pfizer-BioNTech] or suggest a small difference because of uncertainties," the FDA said, later calling evidence of a risk difference between the two products "inconclusive."

Committee members signaled continued concern about the side effect but concurred with the FDA that a notable risk difference between Moderna's vaccine and Pfizer's was unclear.