Uncertainty Looms Over Spring Covid-19 Boosters for Vulnerable Americans

US officials are considering offering vulnerable Americans another bivalent booster shot as studies show the effectiveness of Covid-19 vaccines fades after six months. The bivalent booster is recommended for all Americans aged five and older at least two months after their last dose of a vaccine or three months after a Covid-19 infection. The UK and Canada have already begun allowing certain people to get another bivalent booster. However, the FDA's emergency use authorization for the bivalent vaccines doesn't allow doctors to prescribe another booster for vulnerable people or for the CDC to recommend one.