FDA advisers recommend updating Covid vaccines

Advisers to the Food and Drug Administration voted Thursday to back a plan whereby all Covid vaccines would move to the formulation used for the updated boosters, a step toward the goal of creating a single annual Covid shot for most Americans.

The panel said that a single vaccine would both be more effective and less confusing to both patients and health care workers.

The panel voted 21-to-0 to direct vaccine manufacturers Pfizer/BioNTech, Moderna, and Novavax to “harmonize” the primary series of their vaccines — the first doses that people receive — with the new booster shots that contain both the original strain of the SARS-CoV-2 virus and a new Omicron strain.

Members of the panel were also supportive of the FDA’s plan to move to a single annual vaccine dose for most Americans, which will be matched annually to circulating strains of the SARS-CoV-2 virus. The idea is that this would better protect recipients and allow for a more smooth vaccine rollout. For older people, immunocompromised individuals, and young children, two doses would be given, according to FDA plans.

However, the FDA did not ask the panel to vote on the components of the new plan.

“I think this is a reasonable approach. We have to keep reminding ourselves that this is not influenza and we need to keep paying attention to that to make sure we don’t just follow that dogma because we’re used to doing it,” said Bruce Gellin, a temporary voting member of the panel and chief of global public health strategy for the Rockefeller Foundation’s pandemic prevention institute. “We’ll try this this time. I don’t think we’re setting it in stone and we’ll see how it goes. We may need to adjust along the way.”

A continued Covid vaccination program represents a huge challenge for the U.S. government. Most people received the original two doses of the mRNA vaccine, with 229.5 million people, or 75% of those over age 5, having rolled up their sleeves. But a much smaller number of Americans – 50.6 million, or 16% of those eligible – have gotten the bivalent booster.

A wealth of data was presented by the FDA, the Centers for Disease Control and Prevention, and the companies that manufacture the vaccines showing that the new boosters result in higher antibody levels against new strains of the virus, including a Moderna study in the U.K. that directly compared a new bivalent booster with the original booster. Generally, the panel seemed to support the idea of moving to the new boosters.

But the need was also clearly highest in older people, who die of Covid in disproportionate numbers. According to data presented by the CDC, death rates from Covid over the past year were 1.3 per 1,000 in people aged 65 to 74 years and 5.1 per 1,000 in those over 75. The latter is 60 times the rate in adults aged 18 to 49 years.

Nicola Klein, director of the Kaiser Permanente Vaccine Study Center, presented results of a study that might indicate a link between the Pfizer vaccine and stroke in older people, but both the panelists and the FDA tended to believe it was a finding that might not hold up with further study.

However, little data was presented on the risk of myocarditis, a rare side effect of the vaccine that shows up mainly in men and adolescent boys.

The panelists did seem to believe that the idea of another annual shot, at least next year, was warranted by the current data. But several panelists hoped that a better vaccine would emerge over time, though it’s not clear how a new vaccine would be developed. And others said that many important questions about how vaccines should be used would require more data to answer.

“I think it’s quite reasonable to talk about another one for the fall,” said Eric Rubin, a panelist and the editor of the New England Journal of Medicine. “It’s hard to say that it’s going to be annual at this point.”

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