Sen. Bill Cassidy (R-La.) called for the delay of this week’s meeting of a federal vaccine advisory panel handpicked by Health and Human Services Secretary Robert F. Kennedy Jr, citing concerns about members’ lack of experience and potential bias towards vaccines.

“Wednesday’s meeting should not proceed with a relatively small panel, and no CDC Director in place to approve the panel’s recommendations,” Cassidy wrote in a post on X late Monday evening.

He noted that members of the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices “do not have significant experience studying microbiology, epidemiology or immunology,” and some may even have a “preconceived bias against” mRNA vaccines.

Cassidy’s comments represent the strongest statement he’s made to date about Kennedy or his actions, though he did not mention the secretary by name. Cassidy voted to confirm Kennedy despite publicly wavering over the nomination and sharply criticizing his views on vaccines. 

Kennedy fired the entire 17-member ACIP panel less than two weeks ago, arguing a “clean sweep” was needed to purge conflicts of interest and help restore trust in vaccinations and public health.  

The move was an unprecedented escalation in Kennedy’s quest to reshape the nation’s vaccine policy and seemingly ignored one of the key promises Cassidy said he extracted from the longtime anti-vaccine activist.

He then appointed eight new members, several of whom are vocal vaccine critics. 

If the meeting isn’t delayed, Cassidy said, the panel’s recommendations “could be viewed with skepticism, which will work against the success of this Administration’s efforts.”

The two-day meeting begins Wednesday. Part of the agenda includes discussion and a vote on recommendations concerning thimerosal, a vaccine ingredient wrongly linked to autism that Kennedy has long called to be banned.