The cancellation plays into fears among scientists who worry that Robert F. Kennedy Jr. will use his position as health secretary to sow doubts about vaccines.

A meeting of a committee which advises the U.S. Food and Drug Administration on vaccine policy has been canceled, a committee member told Reuters, the second such disruption to a federal vaccine advisory panel since Robert F.

It comes as RFK Jr., a vaccine skeptic who now leads the Department of Health and Human Services, makes moves that could affect vaccination uptake and policy.