Centers for Disease Control and Prevention vaccine advisers Thursday overwhelmingly recommended the use of Moderna’s and Pfizer’s updated COVID-19 booster shots, arguing they could help stave off a winter wave of infection.

In two separate 13-1 votes, the CDC Advisory Committee on Immunization Practices recommended both vaccines, sending the recommendations to CDC Director Rochelle Walensky for her endorsement. Walensky endorsed the recommendations within hours of the committee vote, saying in a statement that updated boosters “can help restore protection that has waned since previous vaccination.” 

The decision, combined with the Food and Drug Administration’s decision to authorize the boosters Wednesday, clears the way for the updated boosters’ quick release. 

Broad uptake of these boosters in September could prevent more than 9,700 deaths and more than 100,000 hospitalizations compared to a November rollout, according to CDC data. Vaccine advisers agreed that it was important to move forward now, rather than wait for more clinical trial data.

The vaccine advisers debated but eventually agreed that the animal studies used to test the shots were enough to recommend use, and agreed that scientists have seen a “very good correlation” between mice, nonhuman primates and humans. Clinical studies in humans are ongoing and will become available in the coming months.

“This vaccine has the potential to decrease hospitalizations and even deaths. … We don’t usually have too much clinical information for efficacy when we are thinking about changing influenza vaccines. It is part of the same scaffolding, the same roof,” said Sarah Long, a pediatrics professor at Drexel University and CDC vaccine adviser.

The updated shots are necessary going into the fall, advisers said, because while the original COVID-19 vaccines provide high protection against severe disease, the original shots provide less protection against asymptomatic or mild disease as the virus evolves. The new boosters also increase protection against severe disease and could likely improve immune response to future variants, they said.     

Going forward, the CDC is looking to simplify the COVID-19 booster program, and if SARS-CoV-2 becomes a seasonal virus, a seasonal vaccination program similar to the flu shot may make sense, said Sara Oliver, the lead of the CDC vaccine advisory work group. 

“We’re being asked to take a leap into a whole new dimension of how we move forward with COVID vaccination, and the data that’s been presented is very reassuring,” said Lynn Bahta, a CDC vaccine adviser and immunization consultant in the infectious disease division of the Minnesota Department of Health. 

The updated shots target both the original strain of COVID-19 as well as the BA.4 and BA.5 strains of omicron, the two most prevalent strains right now. The boosters will take the place of the boosters already on the market and will be available to individuals at least two months after their original series or most recent booster. Moderna’s shot will be available to adults 18 and older, and Pfizer’s will be available to individuals 12 and older.

CDC data proved that both bivalent boosters increased immune response in those who have completed a primary series and a previous booster. Compared to the original booster dose, the updated boosters had a better response to omicron and equal response to the original strain of the virus. 

Agency safety data showed that myocarditis rates are lower after a booster dose than a primary series of vaccines. 

“We fully acknowledge that we are in a different situation now than we were in 2020 or 2021,” Oliver said, noting that many people not only have received vaccines but have also been infected by the virus. Still, a CDC survey found that 72 percent of people eligible for a bivalent booster would “probably” or “definitely” receive an updated shot — a much higher rate of uptake than the original booster campaign. 

The board said that if a person has a current COVID-19 infection, bivalent booster vaccination should be delayed at least until they recovered.

The updated shots will coincide with the fall influenza season, and the booster shot and flu vaccine can be administered at the same time. The CDC advisers recommended providers offer flu and COVID-19 vaccines during the same visit.