FDA approves Moderna & J&J boosters, allows mixing doses

The FDA on Oct. 20 amended the emergency use authorizations for the COVID-19 vaccines made by Moderna and Johnson & Johnson, allowing for the administration of an additional dose.

Seven things to know:

1. A single booster dose of Moderna's vaccine may be administered at least six months after the initial vaccination series for people ages 65 and older, adults at high risk of severe COVID-19 infection or adults whose jobs put them at a higher risk of COVID-19 infection.
   
   
2. Moderna's booster dose is half the dose administered in its primary series.
   
   
3. When deciding whether to amend Moderna's emergency use authorization, the FDA analyzed immune response data from 149 participants ages 18 and older who received a booster dose at least six months after their second dose. The agency compared the data to the immune responses of 1,055 study participants after completing their two-dose series, finding the additional shot raised immunity levels.
   
   
4. The FDA also examined additional data from Moderna comparing the rates of COVID-19 cases accrued from July through August, when the delta variant spread rapidly. The agency found the data suggested the vaccine's efficacy wanes over time.
   
   
5. A single booster dose of Johnson & Johnson's vaccine may be administered at least two months after initial vaccination to Americans ages 18 and older.
   
   
6. When deciding whether to amend Johnson & Johnson's emergency use authorization, the FDA evaluated immune response data from 39 participants ages 18 and older, including 15 people who were ages 65 and older. The data showed their immunity levels rose when they received a booster dose about two months after their first dose.
   
   
7. The FDA is allowing those who are eligible for boosters to receive one made by a different drugmaker than the one that made the vaccine with which they were initially inoculated.