CDC Recommends New Omicron COVID Boosters

A committee of doctors and other medical experts who advise the US Centers for Disease Control and Prevention voted Thursday to endorse updated COVID-19 boosters from Moderna and Pfizer-BioNTech that target the BA.4/BA.5 subvariants of omicron. Shortly after, CDC Director Dr. Rochelle Walensky accepted the panel's vote -- the final regulatory step needed to start the fall COVID-19 campaign in the US. Shots should be available at pharmacies throughout the US in the coming days.

The US Food and Drug Administration authorized both boosters one day earlier. Moderna's vaccine is authorized for adults 18 and older, while Pfizer's is for people 12 and older. 

"The updated COVID-19 boosters are formulated to better protect against the most recently circulating COVID-19 variant," Walensky said in a statement. "They can help restore protection that has waned since previous vaccination and were designed to provide broader protection against newer variants." 

To be eligible for a booster, you must have waited at least two months since your last COVID-19 vaccine dose, whether it was a primary vaccine or a booster shot. Some people, including those who had COVID-19 within the last three months, will probably be better off waiting longer than two months between doses, some advisory panel members argued. More details and individual recommendations are expected from the CDC's clinical considerations in the coming days.

Pressure to get new COVID-19 vaccines that target more relevant strains of the virus has been mounting ahead of fall and winter, when we should expect another wave of cases as people spend more time indoors. As part of the sped-up schedule, the FDA made its authorization based on human clinical data on a slightly different BA.1 bivalent booster as well as data from animal studies on the BA.4/BA.5 bivalent booster, not clinical trial data on the BA.4/BA/5 booster specifically.

Part of the reason the FDA took this approach may be that bivalent boosters are relatively easy to modify, similar to how we modify the influenza vaccines every year, according to a tweet from FDA Commissioner Dr. Robert Califf. 

"Bivalent and multivalent vaccines are very common and modifying a vaccine to include different virus strains often does not require a change in other ingredients," Califf said last week. "FDA has extensive experience with reviewing strain changes in vaccines, as is done with the annual flu vaccine."

The COVID-19 vaccines and boosters have remained effective at preventing severe disease and death from COVID-19, even as their infection protection has waned as the virus evolves. According to June data, adults 50 and older who received two booster doses were 14 times less likely to die from COVID-19 than unvaccinated adults of the same age, and three times less likely to die than adults who received one booster. 

Also in June, unvaccinated people age 5 and older were eight times more likely to die from COVID-19 than people who were fully vaccinated with at least one booster, according to data shared at the CDC meeting. This was a decrease from 20 times during January-March 2022, however, illustrating the waning immunity of the original COVID-19 vaccines. 

Only about 52% of American adults received the first booster dose, and a smaller number received the second, raising questions about how many will opt for maximum protection with the updated boosters as we move into the fall season. However, 72% of participants in a survey that was shared at the CDC meeting Thursday said they'd be open to getting an updated booster. 

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