FDA on Wednesday authorized booster doses of the Moderna and Johnson & Johnson Covid-19 vaccines and allowed Americans to switch vaccine brands for their booster.
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FDA authorizes 'mixing and matching' vaccines for boosters
In a statement, FDA said that, for individuals who previously received a two-dose series of the Moderna vaccine, a half-dose booster can be given six months later. Meanwhile, for those who initially received a single dose of the J&J vaccine, a booster can be given two months later.
"The available data suggest[s] waning immunity in some populations who are fully vaccinated," acting FDA Commissioner Janet Woodcock said. "The availability of these authorized boosters is important for continued protection against Covid-19 disease."
The agency also said that anyone who's eligible to receive a booster dose could receive any currently authorized Covid-19 vaccine for their booster.
So far, research suggests switching Covid-19 vaccines is safe and effective. For example, a recent study from NIH found that boosters of all three authorized Covid-19 vaccines generated a strong immune response, with the vaccines from Moderna and Pfizer-BioNTech leading to larger increases in antibody levels than the J&J vaccine.
Vaccine mixing may help simplify the booster rollout
According to the New York Times, state health officials have been requesting an option to mix and match vaccines, arguing it would simplify the booster rollout.
"The No. 1 thing I heard from state health secretaries was the need for permissive language around a mix-and-match approach," said Nirav Shah, Maine's top health official and the president of the Association of State and Territorial Health Officials.
According to the Times, switching vaccine brands can be helpful if patients had adverse reactions to their initial vaccines or if providers do not have access to a patient's original vaccine. For example, Clay Marsh, West Virginia's Covid-19 czar, said the state had a greater supply of Moderna and Pfizer-BioNTech vaccines than J&J.
"Being able to interchange these vaccines is a good thing—it's like what we do with flu vaccines," said Peter Marks, director of FDA's Center for Biologics Evaluation and Research. "Most people don't know what brand of flu vaccine they received."
In addition, other health officials said the option to switch vaccines could streamline the administration of boosters, the Times reports, since providers would not have to match patients to their initial vaccine brands first.
What's next?
On Thursday, CDC's Advisory Committee on Immunization Practices (ACIP) will meet to discuss recommending booster shots of Moderna's and J&J's vaccines to CDC Director Rochelle Walensky, who has the authority to issue final recommendations.
In September, ACIP recommended boosters for some populations but did not support them for those whose jobs put them as risk of exposure to the coronavirus. Walensky, however, ultimately decided to recommend boosters for those populations.
Given that prior disagreement, "[i]t is going to be a difficult meeting, because I suspect that the science won't have changed much," said Sarah Long, a pediatrician and infectious disease expert at Drexel University. "I can see making it clear that we still don't think this is the right approach, and Dr. Walensky would have to override it."
According to federal health officials, ACIP is likely to recommend patients receive a booster shot of the same brand as their initials series but will allow mixing and matching of vaccines if that isn't possible. (LaFraniere/Weiland, New York Times, 10/21; Branswell/Herper, STAT News, 10/20; Chen, Axios, 10/20; Perrone/Neergaard, Associated Press, 10/21; Loftus/Schwartz, Wall Street Journal, 10/20; Walker, MedPage Today, 10/20; Jeong et. al., Washington Post, 10/21; Gardner, Politico, 10/20; Weixel, The Hill, 10/21; Joseph/Branswell, STAT News, 10/21; Mandavilli, New York Times, 10/21)