The preservative thimerosal has been removed from all but a few vaccines, and studies have confirmed no link to neurodevelopmental issues including autism. So public health experts were puzzled when it appeared on the agenda for this week’s meeting of outside vaccine advisers to the US Centers for Disease Control and Prevention.

The move could shift long-standing practices of how and when children are immunized in the United States.

Lyn Redwood, who spread debunked claims about vaccines, will be in the CDC's Immunization Safety Office, multiple CDC officials tell CBS News.