The Centers for Disease Control and Prevention's vaccine advisory committee wrapped up the first day of its meeting since Health and Human Services Secretary Robert F. Kennedy Jr. dismissed the entire panel and appointed his own hand-selected members.

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

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.