A Food and Drug Administration advisory committee on Thursday cast doubt on the move toward an annual Covid booster for most adults and children, saying many questions about the virus remain unanswered.
The FDA convened its Vaccine and Related Biologics Products Advisory Committee to discuss how Covid vaccines can move forward.
On Monday, the agency published briefing documents proposing annual Covid shots that target the latest versions of the virus — an approach similar to the annual flu shot.
But at Thursday’s meeting, several committee members said they were hesitant to make any decisions about when vaccines would be administered, since the virus is still so new.
Unlike the flu, which thrives in the winter months, the spread of Covid has been largely erratic, constantly mutating into new forms and failing to stick to predictable seasonal patterns. A common refrain at the meeting was not like the covid flu.
“We don’t know what’s going to happen,” said Dr. Eric Rubin, editor-in-chief of the New England Journal of Medicine. “It’s hard to say at this point it will be annual.”
A virus may mutate several times a year and become more virulent or more immune-disrupting—or it may not.
Tufts University School of Medicine pediatrician Dr. “We may or may not require annual vaccinations,” Cody Meissner said. “It’s too early, I think, in this process to answer that.”
Other committee members said they were concerned about the amount of protection people would have against the virus if the U.S. moved to an annual vaccination schedule, and whether it would be better to wait for more effective vaccines.
Thursday’s meeting included a presentation by the National Institutes of Health on the next generation of Covid vaccines that could provide broad protection against both known and unknown strains of the virus – although officials noted that a broadly protective vaccine is likely a long way off.
The effectiveness of Pfizer-BioNTech and Moderna’s Covid vaccines lasts for months or years, while protection against infection wanes after only a few months.
“We need broader protection,” Dr. Pamela McInnes, retired deputy director of the National Center for Advancing Translational Sciences at the National Institutes of Health. “We don’t want to chase this virus.”
At Thursday’s meeting, the FDA’s top vaccine regulator, Dr. Peter Marks admits that it may not be possible to simplify the Covid vaccination schedule exactly like the flu.
The FDA proposed that a committee meet each June to select a strain or strains for the annual vaccine, which would give producers enough time to make enough for the fall campaign.
Director of the Division of Viral Products in the FDA’s Office of Vaccine Research and Review, Dr. Jerry Weir said that even if the U.S. adopts an annual approach, if a new, more dangerous variant emerges, the agency will still likely hold an emergency meeting to discuss whether new boosters are needed.
Some committee members said they would prefer to have more annual meetings on Covid vaccines.
Meeting once a year, they said, could give the public the impression that Covid, like the flu, is only a threat in the fall and winter months — which it isn’t.
“I think this pattern is not the flu at all,” said Dr. Henry Bernstein said. “We need to communicate that there is still value in getting vaccines outside the normal influenza window.”
They also questioned whether offering boosters in the fall meant people couldn’t get boosters at any other time of the year, meaning people had a limited window of time to be protected.
While the committee was undecided about moving forward with annual boosters, they were certain about the need to simplify the format for vaccines.
Currently, a bivalent vaccine targeting the Omicron subvariants BA.4 and BA.5, other than the original strain of the virus first identified in Wuhan, China in 2019, is only available as a booster shot. The primary vaccine series, which is given to anyone who has not been vaccinated, still targets only the original strain.
In a unanimous vote, the committee recommended using the bivalent formulation in all Covid vaccines going forward, not just booster shots.
The FDA is not obligated to accept its committee’s recommendations, although it often does.