FDA panel recommends updating Covid-19 vaccines; here's why

The Food and Drug Administration's external scientific committee unanimously recommended Thursday that Covid-19 vaccines be updated to thwart new versions of the virus, which is mutating about twice as fast as the flu, vaccines for which are updated annually, Katelyn Jetelina reports in Your Local Epidemiologist.

Also, "The current Omicron variant (XBB) circulating is meaningfully different than other Omicron variants," Jetelina writes. "Covid-19 vaccines are waning in protection against hospitalization (62% effectiveness has dropped to 24%) and ICU admission, albeit with a smaller decline (69% to 52%). This is happening faster when exposed to XBB virus compared to other Omicron variants."

Hospitals aren't filling up with Covid patients "because vaccine effectiveness now represents the incremental benefit above and beyond the baseline protection in the general population. This is different than when we first introduced vaccines and the general population had a very low immunity wall." In other words, natural immuiity (not just antibodies but other features of the immune system) combined with vaccines provide a relatively high immunity wall.

What's next? "Pfizer, Moderna, and Novavax will start manufacturing millions of vaccines. Once they’re ready, the FDA will approve the updated vaccine," Jeteline writes. Then the committee "will determine who should get the vaccines. Expect this to happen in late summer or early fall."

"Everyone’s curious to see how this year plays out," Jetelina says of her community of interest. "The rest of the year will be very telling as to whether Covid-19 has settled into a seasonal, predictable pattern. Comparing Covid-19 to the flu is helpful, but the viruses, and thus processes, are different. This needs to be communicated better."

She adds, "Don’t let anyone tell you there are no human data on these vaccines. All vaccine manufacturers presented preliminary data on humans and animals. What we do not have yet is the safety of these vaccines when combined with RSV and flu vaccines." RSV is respiratory syncytial virus, which targets mainly the young and the elderly.