Today the U.S. Food and Drug Administration (FDA) authorized COVID-19 booster shots for some groups of people who received the two-dose Moderna and single-dose Johnson and Johnson COVID-19 vaccines.
The Moderna vaccine emergency use authorization (EUA) applies to already fully vaccinated adults age 65 and over, as well as adults ages 18 to 64 who are at higher risk of severe illness because they have an underlying medical condition or job that raises their risk of exposure to COVID-19. For the Johnson and Johnson COVID-19 vaccine (also known as the Janssen vaccine), the EUA allows people age 18 and older to get a second dose as soon as two months after their first dose.
Additionally, the FDA authorized the use of the mix-and-match (heterologous) vaccination strategy, which means that people who are eligible for additional doses can get a COVID-19 booster shot of a different vaccine than that of their primary series. So, for instance, someone who received two doses of Pfizer initially could get a Moderna booster. Or, someone who got the single-dose Johnson and Johnson vaccine could get a Pfizer or Moderna booster dose.
“Today’s actions demonstrate our commitment to public health in proactively fighting against the COVID-19 pandemic,” Janet Woodcock, M.D., acting FDA commissioner, said in a statement. “As the pandemic continues to impact the country, science has shown that vaccination continues to be the safest and most effective way to prevent COVID-19, including the most serious consequences of the disease, such as hospitalization and death. The available data suggest waning immunity in some populations who are fully vaccinated. The availability of these authorized boosters is important for continued protection against COVID-19 disease.”
The Moderna EUA came through after the FDA Vaccines and Related Biological Products Advisory Committee agreed unanimously last week that the booster shots would be safe and effective for people in these groups. The third shot of the Moderna mRNA vaccine is to be given at least six months out from their initial vaccination, and contain half as much vaccine as each of the first two doses. Moderna’s COVID-19 vaccine booster EUA is very similar to the booster shot EUA that the Pfizer/BioNTech vaccine received. (A third dose of both the Moderna and Pfizer/BioNTech COVID-19 vaccines was previously authorized in August for use in severely immunocompromised people at least 28 days after their second shot.)
Despite the unanimous vote, some members of the committee criticized the lack of stronger data supporting the necessity of a booster shot for the Moderna vaccine, the New York Times reported. Some of the real-world data we do have indicate that the efficacy of the Moderna vaccine holds up quite well. (Not to mention, a number of experts question the demonstrated benefit of boosters altogether, especially for people who are not elderly or immunocompromised.)
For instance, a study published by the CDC in September looking at 3,689 hospitalized adults (without immunocompromising conditions) found that the efficacy of the Pfizer/BioNTech vaccine in preventing hospitalization due to COVID-19 fell from 91% to 77% after four months of full vaccination—while the efficacy rate of Moderna’s vaccine barely dipped, from 93% to 92%.