FDA panel endorses booster shot for J&J Covid-19 vaccine October 15, 2021 at 11:32PM

US health advisers endorsed a booster of Johnson & Johnson's Covid-19 vaccine, citing concern that Americans who got the single-dose shot aren't as protected as those given two-dose brands. J&J told the Food and Drug Administration that an extra dose adds important protection as early as two months after initial vaccination — but that it might work better if people wait until six months later.