Variant causing 'breakthrough infections' of fully inoculated people

A man gets a COVID-19 vaccine at a mass vaccination site at the Natick Mall on Wednesday, Feb. 24, 2021, in Natick, Mass. U.S. experts are expected to recommend COVID-19 vaccine boosters for all Americans, regardless of age, eight months after they received their second dose of the shot, to ensure lasting protection against the coronavirus as the delta variant spreads across the country. An announcement was expected as soon as this week, with doses beginning to be administered widely once the Food and Drug Administration formally approves the vaccines. (Matt Stone/The Boston Herald via AP, Po…