Pfizer and partner BioNTech on Tuesday asked the Food and Drug Administration to authorize a booster dose of their coronavirus vaccine for all adults older than 18, pushing the agency to expand the current clearance to include many more Americans.
The application is the second time the companies have sought broad authorization for a third dose of their vaccine. The FDA in September chose to green light an additional shot only for older adults or those at higher risk of COVID-19 due to their health or occupation, after agency advisers opposed offering a booster to anyone over 16 years of age.
An authorization, should the agency grant one, would substantially widen the number of people who could receive a booster. Under current rules, about 100 million people in the U.S. are eligible for an additional dose of either Pfizer's, Moderna's or Johnson & Johnson's vaccines. Boosters of the latter two were cleared in October for older and at-risk adults who had previously received two doses of Moderna's, and for adults over 18 who had had a single dose of J&J's.
While the number of new COVID-19 cases in the U.S. has fallen since their recent peak in September, recent weeks have seen cases plateau at an average of about 70,000 per day. Health officials, meanwhile, are again concerned that holiday travel could spark a new wave of infections.
Broader rollout of booster doses could help prevent so-called breakthrough infections in vaccinated people whose protection may have waned in the months since their initial immunization. But the degree to which an additional dose could help younger, healthy adults has been contested among experts, including advisers to both the FDA and the Centers for Disease Control and Prevention.
More data has been collected, however, since the initial September review by an FDA panel of Pfizer's request for booster clearance in adults over 16. Last month, for instance, the two companies reported results from a large clinical trial that showed a third dose was 96% effective in preventing symptomatic COVID-19 compared to a placebo among people who had previously received two doses of their vaccine.
Real-world evidence from Israel has further bolstered the case for boosters, showing that, after third doses were authorized for all ages, rates of infection and severe disease fell across all age groups.
It's not clear whether the FDA would convene its advisory committee before making a decision on Pfizer's application. The Washington Post and The New York Times both reported the agency was unlikely to do so, citing administration officials.
Some 14% of U.S. adults over 18 and 31% of those over 65 have already received a booster, mostly a third dose of Pfizer's or Moderna's vaccines.