FDA's Vaccines and Related Biological Products Advisory Committee on Friday voted 16-2 against recommending booster shots of the Pfizer-BioNTech Covid-19 vaccine to all adults 16 and older six months after full vaccination, but unanimously voted to recommend the shots to adults 65 and older and those at high risk for severe Covid-19.
What does the committee's recommendation mean?
In August, the Biden administration announced that it intended to make booster shots available for all Americans who received an mRNA vaccine eight months after their second shot beginning the week of Sept. 20, pending FDA authorization and CDC recommendation.
The FDA committee's recommendation is narrower, however, and would not include boosters for most people under the age of 65.
FDA is expected to make a decision regarding booster shots in coming days, the New York Times reports, and is not required to follow the recommendation of the advisory panel.
In a statement following the FDA panel's vote, Kathrin Jansen, head of vaccine research and development for Pfizer, said the company "will work with the FDA … to address the committee's questions, as we continue to believe in the benefits of a booster dose for the broader population."
Details on the meeting
At the meeting, members of the advisory committee—which consisted of vaccine experts, immunologists, pediatricians, infectious disease specialists, and public health experts—debated whether available data suggests booster shots should be available for everyone over the age of 16.
William Gruber, SVP of vaccine clinical research and development at Pfizer, said that multiple studies show people's immunity to the coronavirus wanes over time. "Israel and the United States real-world evidence suggests that vaccine efficacy against Covid-19 infection wanes approximately six to eight months following the second dose," he said.
According to Gruber, Pfizer's data shows booster shots restore and even enhance immunity and that they don't carry any worse side effects than the initial, two-dose regiment.
However, Phil Krause, deputy director of FDA's Office of Vaccines Research and Review, noted that Pfizer's data has not been peer-reviewed. "One of the issues in this is that much of the data that's been presented and being discussed today is not peer-reviewed and has not been reviewed by FDA," Krause said.
The data in Israel also was focused on adults age 60 and over, who were the first group made eligible to receive boosters in the country. As such, many members of the FDA committee doubted that the data supported booster shots for younger U.S. populations.
And Michael Kurilla, an infectious disease specialist at the National Center for Advancing Translational Sciences, said that Pfizer's data heavily relies on antibody measurements without looking at other elements of the immune response.
"It's a little disappointing that there's been very little reporting of the cellular immune responses and an entire focus on the neutralizing antisera," Kurilla said. "Which clearly for that population at high risk is absolutely essential, but for the broad population in terms of their protection, which seems to be holding up well over time—[that] should be because of adequate cellular immune responses but we have no indication of that."
Why Fauci believes boosters for younger adults are still coming
Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said he believes the Biden administration's plan announced in August lines up with the advisory panel's recommendation and that the "proper regimen" for mRNA shots will eventually include two shots and a booster.
"You want to do that according to what the data tells you, including the risk-benefit ratio, particularly for the younger people who do not generally get as much severe disease as the elderly and others," Fauci said. "So, I believe that there's a good chance that as we get into the coming months, into the next year, that you will see the data pointing to the benefit of having a much broader blanket of people."
Data on booster shots for the Covid-19 vaccines made by Moderna and Johnson & Johnson are also "literally a couple to a few weeks away," Fauci added.
Fauci advised Americans to exercise patience and wait until they're eligible to get a booster shot.
NIH Director Francis Collins said he'd be surprised if booster shots aren't made available for the general population, despite the FDA panel's recommendation.
"I think the big news is that they actually did approve the initiation of boosters, and, remember, they're taking a snapshot of right now. We're going to see what happens in the coming weeks," Collins said. "It would surprise me if it does not become clear over the next few weeks that administration of boosters may need to be enlarged."
Collins added he's unsure whether booster shots will be needed by "absolutely everyone," but said he'd be "surprised" if booster shots aren't recommended for those under 65 in the coming weeks. (Fox et al., CNN, 9/18; Thomas, New York Times, 9/20; Gardner, Politico, 9/17; Choi, The Hill, 9/19; Owens, Axios, 9/20; Crummy, Politico, 9/19; Beals, The Hill, 9/19)