Kennedy’s unorthodox ideas about a wide range of health subjects may appear disparate to those who haven’t trawled through his more than a dozen books.

The Department of Health and Human Services sent Congress a document to support Secretary Robert F. Kennedy Jr.’s decision to change federal vaccine recommendations that cited unpublished or disputed studies and misrepresented other findings,

Multiple new members have voiced anti-vaccine views that are not based in scientific evidence. Their actions could shape the way insurers, doctors and the public make decisions about immunizations.