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Pfizer/BioNTech's COVID-19 vaccine was authorized for use in adolescents as young as 12, the first in the U.S. to receive emergency use authorization (EUA) in this younger age group, the on Monday.

The agency amended the existing EUA to include teens ages 12 to 15 after the vaccine demonstrated 100% efficacy against symptomatic disease in this age group in a randomized trial. Pfizer's vaccine was first authorized in December 2020 for people 16 and older.

FDA officials said if the vaccine is recommended by the CDC's Advisory Committee on Immunization Practices (ACIP), it will be administered as a series of two shots, 3 weeks apart, with the same dose that adults receive.

At a media briefing on Monday night, Acting FDA Commissioner Janet Woodcock, MD, said that she hoped this decision would help "instill confidence in a parents' decision" to have their children vaccinated, and pointed to FDA fact sheets for and to answer concerns and offer guidance.

"While children generally have milder symptoms ... they're not immune to this virus," she added.

Peter Marks, MD, PhD, director of the FDA Center for Biologics Evaluation and Research, stressed the need to vaccinate this age group on a population-health level.

"This is part of the totality of getting our country protected against COVID-19," he said. "We're pretty serious about the need to get vaccination rates up."

Marks characterized the EUA as a "relatively straight-forward decision" based on two sets of data.

In the 2,260-person phase III trial, which randomized teens 1:1 to two doses of either placebo or vaccine, 16 cases of COVID-19 were observed in the placebo group versus none in the vaccine group.

Marks also said the data involved a process called "immunobridging," where lab results from 190 vaccinated adolescents ages 12 to 15 was compared with that of 170 vaccinated people ages 16 to 25. Lab results in the younger subset of participants showed that the vaccine generated a strong immunogenic response 1 month following the second dose, which was non-inferior to SARS-CoV-2 neutralizing antibody geometric mean titers generated in the older group.

"We are very comfortable with the data we have," he said.

The vaccine was generally well tolerated, and side effects were consistent with the older age group. The most common side effects were pain at the injection site, tiredness, headache, chills, and joint pain, which lasted 1 to 3 days following vaccination.

Presumably, more detailed data will be presented at Wednesday's scheduled emergency ACIP meeting, which will review the data and vote on adding the vaccine to the recommended child and adolescent immunization schedule in this age group.

Marks noted that while FDA is comfortable using the same dosing schedule in adolescents as adults, "as we get down to younger children, different doses of the vaccine" will be needed.

FDA has meeting on June 10, in part of discuss the criteria used for authorization in younger children.

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