As States Defy U.S. on Boosters, Health Experts Raise Concerns

Nine states in the U.S. are now offering booster shots to all adults, contradicting federal guidance and reigniting the national debate on eligibility for supplemental vaccine doses.

Currently, booster shots in the U.S. should be limited to those with pre-existing medical conditions and people 65 or older, according to guidelines from the Centers for Disease Control and Prevention. But so far, health departments in New York, New Jersey, California and six other states have independently broadened access to Covid-19 boosters, and that number is expected to grow. The diverging guidance has some health experts worried.

“I think that it is ...