FDA panel approves path toward one-shot yearly COVID vaccine

COVID-19 vaccination took a step closer to evolving into a single yearly shot.

A Food and Drug Administration advisory panel voted unanimously yesterday that deploying one vaccine each year is the best way to manage the virus, similar to how the flu is handled.

After meeting for about 10 hours, the Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted 21-0 to use a “harmonized” vaccine that mixes the monovalent with the bivalent vaccine developed to fight the omicron variant as the yearly shot. In addition, the panel said that the bivalent vaccine can be used as the first shot given to those who haven’t been vaccinated yet.

Eric Rubin, M.D., a panelist and the editor of The New England Journal of Medicine, told Fierce Healthcare that “I think that everyone agreed with the idea that, given what we know now, it made sense to schedule vaccines in a way that makes it most convenient and most likely that people will actually take them. However, there is a lot we don’t know and if we learn more—I hope we do—it might require a change in that strategy.”

Rubin labeled what might be the optimal interval for vaccine dosing as one of the “big unknowns” for both the magnitude and breadth of the response. “And, of course, what we really care about is protection rather than antibody levels so obtaining these data will take some work," he said

Perhaps the most surprising “yes” vote was by panel member Paul Offit, M.D., the director of the Vaccine Education Center at Children’s Hospital of Philadelphia, who often votes against the majority. For instance, Offit was one of two members of the panel who voted against approval of the bivalent vaccine last June, because he said that the increase in antibodies did not provide a clinically more significant difference in protection from severe disease over the monovalent vaccines.

Although he voted “yes” yesterday, Offit and Jerry Weir, Ph.D., director of the FDA's division of viral products, did have an intense discussion about the value of the bivalent vaccine.

“One of the things that surprised me was when you likened the omicron strain to a shifted virus,” Offit said. “Clearly, this is an evasive strain, but it’s evasive mainly against mild disease. If you’ve been vaccinated or infected or both, you generally are protected against severe disease. I would say that this is a drifted virus. If we truly are looking at a shifted virus, then we truly are starting out all over again. But that’s not this virus.”  

Weir said he “would argue that with [Offit] only in the sense that up until omicron all the drifting had been 1, 2 or 3 amino acids. And then, all of a sudden, it was 35 different amino acids. It was quite a dramatic change.”

Offit said that these were still “epitopes recognized by T cells. That’s why I think of it as drifted, and not shifted. The good news is that ever since Wuhan up to XBB 1.5., you still have conserved T-cells epitopes in 80%, 85% which is why we’re still protected against the disease.”

Offit alluded to the panel’s decision to have Pfizer-BioNTech, Moderna and Novavax create the new “harmonized” vaccine, but noted that the data used for that advice seem to make the vaccine more of a bivalent than a monovalent.

“You’re giving 30 or 60 micrograms for Pfizer, 50 micrograms for Moderna. Is that where you think we are headed? Where we wouldn’t be using the ancestral strain anymore and is there still a reason to use the ancestral strain?” he asked.

Weir responded that that’s one of the issues that should be discussed at the next VRBPAC meeting.

“My gut feeling—my gut doesn’t produce the data—but my gut feeling is that a monovalent would have been a little better now than the bivalent. But I think there were reasons that we chose the bivalent which were pretty good at the time. The real question is where are we headed?" Weir said. "I don’t know. We evaluate the data that we have at the time, and we make the best choice that we can. If that’s the bivalent, maybe that’s what we do. If that’s the monovalent, then that’s what we do. But I think we just follow the data we have.”