An advisory panel to the Food and Drug Administration offered a limited endorsement of booster shots of the Covid-19 vaccine from Pfizer Inc. and BioNTech SE , recommending injections for people 65 and older or at high risk of severe disease but stopping short of justifying them for the broader population.
The outside panel’s action comes as the dangerous Delta variant of the coronavirus continues to spread in the U.S. and federal health officials hope that additional doses of approved vaccines will sustain protection in people who have been previously vaccinated.