Why is a fourth dose of a Covid vaccine necessary for some? Elizabeth Tracey reports


Seems like we’ve barely made it through third doses of Covid vaccines for many, and now a fourth dose is in the offing for some groups of people. Lisa Maragakis, an infectious disease expert at Johns Hopkins, explains why.

Maragakis: We’re not sure exactly how far out but a number of months later you’re going to be less protected than you were shortly after getting the vaccine, and that’s where the boosters come in, so I would encourage everyone who’s eligible to get a booster to get a booster, if you’ve gotten the two initial ones and a booster should you get another one? And that’s where some people, particularly those who are older individuals or who are at highest risk for severe disease, go for it if you’re in one of those higher risk groups.  :31

Maragakis notes that only the Pfizer and Moderna vaccines were authorized as a fourth or booster dose of vaccine, for those 50 years of age or older or who have health conditions that may put them at higher risk for severe infection. At Johns Hopkins, I’m Elizabeth Tracey.