Dr. Noel Brewer, a former ACIP member removed by Kennedy and a professor in the department of health behavior at the University of North Carolina Gillings School of Global Public Health, told ABC News that since the upheaval of the ACIP, vaccination has changed in the U.S. in a "fundamental" way and that the committee has "lost credibility."

Recently removed members of a Centers for Disease Control and Prevention (CDC) vaccine advisory panel warn that Health and Human Services (HHS) Secretary Robert F. Kennedy Jr.’s move to replace them shows he is “abandoning” rigorous scientific review and open deliberation.

Monarez, 50, was named acting director in January and then tapped as the nominee in March after Trump abruptly withdrew his first choice, David Weldon.