WASHINGTON — Federal regulators weighed in for the first time Friday on the safety and efficacy of a coronavirus vaccine for children 5 to 11, saying that the benefits of staving off Covid-19 with the Pfizer-BioNTech vaccine outweigh the risks of side effects in the age group.
The analysis came on the same day that Pfizer posted data showing that the vaccine had a 90.7 percent efficacy rate in preventing symptomatic Covid-19 in a clinical trial of 5- to 11-year-olds.
The findings could add momentum for F.D.A. authorization of the pediatric dose on an emergency basis, perhaps as early as next week, opening up a long-awaited new phase of the nation’s vaccination campaign. The agency’s independent vaccine expert committee is set to vote Tuesday on whether to recommend authorization.
In a briefing document posted on the F.D.A. website, the agency said it had balanced the dangers of hospitalization, death or other serious consequences from Covid-19 against the risk of side effects. That included myocarditis, a rare condition involving inflammation of the heart muscle that has been linked to the Pfizer-BioNTech and Moderna vaccines, especially among young men.
“The overall analysis predicted that the numbers of clinically significant Covid-19-related outcomes prevented would clearly outweigh the numbers of vaccine-associated excess myocarditis cases,” regulators wrote.
As is customary, the regulators took no stance on whether the new use of a vaccine should be authorized.
If the F.D.A. rules in favor of authorization and the Centers for Disease Control and Prevention and its own panel of vaccine experts agree, the 28 million children in that age group could become eligible for shots in the first week of November.
“There’s a lot of data to be encouraged by,” said Dr. Kathryn M. Edwards, a professor of pediatrics in the division of infectious diseases at Vanderbilt University School of Medicine. She said the results exceeded the protection offered by the best flu vaccine and could eventually lead to the easing of restrictions intended to prevent elementary school children from contracting the virus.