As many remain unvaccinated, debate grows over need for booster Covid shots

Experts say to prevent the coronavirus from morphing into even more dangerous forms than the Delta variant, the more urgent need is to protect the unvaccinated.

Wading into an acrimonious debate over booster doses, researchers in Israel reported on Wednesday that a third dose of the Pfizer-BioNTech coronavirus vaccine can prevent both infections and severe illness in adults older than 60 for at least 12 days.

The study, published in the New England Journal of Medicine, is the latest salvo in the conflict over whether booster doses are needed for healthy adults and whether they should be given out, as the Biden administration plans to do, when so much of the world remains unvaccinated.

Several independent scientists said the cumulative data so far suggest that only