The company hopes to apply to the Food and Drug Administration in September for emergency authorization of the vaccine for children ages 5-11. Results for children ages 2-5 could be available soon after that, according to Kit Longley, a spokesperson for Pfizer.
Data from the trial for children between 6 months and 2 years old could arrive in October or November, followed by a potential submission to the FDA shortly thereafter, Longley added.
The Pfizer-BioNTech vaccine was authorized last month for use in children ages 12-15.
Based on data from an earlier study that assessed safety, Pfizer will give two doses of 10 micrograms each — a third of the dose given to adolescents and adults — to children ages 5-11, and two doses of three micrograms each to children 6 months to 5 years.
“We take a deliberate and careful approach to help us understand the safety and how well the vaccine can be tolerated in younger children,” said Dr. Bill Gruber, a senior vice president at Pfizer.
The study will enroll up to 4,500 children at more than 90 clinical sites in the United States, Finland, Poland and Spain. Pfizer’s researchers plan to submit the full data from the trials this summer for publication in a peer-reviewed journal.
In March, Moderna began testing varying doses of its vaccine in younger children. That trial aimed to enroll 6,750 healthy children in the United States and Canada. Results are not expected till the end of the summer, and the vaccine’s authorization by the FDA will take longer.
“I think it’s going to be early fall, just because we have to go down in age very slowly and carefully,” Moderna’s CEO, Stéphane Bancel, said Monday.
The company announced late last month that its vaccine was powerfully effective in 12- to 17-year-olds and it plans to apply to the FDA for authorization in that age group. Last week, Moderna also asked the agency for full approval of its vaccine, rather than the emergency use for which it is currently authorized.
The United States will not be the first country in the world to authorize a coronavirus vaccine for young children. China has approved Sinovac’s vaccine for children as young as 3 years old, according to the company’s chairman. The approval has not been officially announced.