The Food and Drug Administration authorized booster doses for the Moderna and Johnson & Johnson COVID-19 vaccines, following its authorization of a third Pfizer / BioNTech shot in September.

On October 20, FDA said that it will allow “mix-and-match” boosters — eligible people who are already fully vaccinated can get a booster dose of any of the three vaccines, regardless of which they started with.

As with the Pfizer / BioNTech booster, the FDA cleared third Moderna shots for vulnerable groups, including people 65 years of age and older, those who are at high risk of severe disease, and people at high risk of exposure to COVID-19 at work.