Johnson & Johnson said Tuesday that Phase 3 studies show that a booster shot of its COVID-19 vaccine increases protection against moderate cases of the virus to 94% in the U.S. Worldwide, J&J said ...

On Sept 22, 2021, Johnson & Johnson released data that answers two questions many people have likely been wondering about its vaccine: How good is it against the delta variant, and do I need a booster ...

Booster shots are being offered to all US adults. Studies suggest boosts can improve protection against symptomatic COVID-19, at least temporarily, with benefits beginning to accrue after a few days.