With the U.S. approval of another COVID-19 shot now expanded to Moderna and Johnson & Johnson recipients, the doors have opened for tens of millions of more Americans to boost their immunity against the coronavirus.
For the mRNA vaccines, Moderna joined Pfizer in getting the nod for booster shots for certain populations at least six months out from their second shots. For the 15 million J&J recipients, the doors were thrown wide open: All J&J vaccinees 18 and older, regardless of health status, are now eligible for a COVID booster just two months post-vaccination.
Adding another layer to decision-making for the vaccinated, the U.S. approved a mix-and-match approach: A booster dose can come from any of the three approved vaccines in the country, regardless of which type a person received first. The option of switching up was partly inspired by the single-dose J&J vaccine, which, while still sufficient, proved less effective against SARS-CoV-2.
For COVID’s high-risk population, taking the shot might feel like a no-brainer. But for others, the booster rollout now underway could raise questions. Professor Ross Kedl, a vaccine expert at the University of Colorado School of Medicine Department of Immunology & Microbiology, addresses some of the top issues below. The interview was edited for length and clarity.