Adams, who served as surgeon general during the first Trump administration, said Kennedy's assertions about the efficacy of mRNA vaccines are "simply not true."

Health Secretary Robert F. Kennedy Jr.'s decision to cut federal funding for mRNA vaccine research is the latest in a series of moves that have the potential to crush future medical breakthroughs and accelerate a brain drain.

The Department of Health and Human Services plans to cancel contracts and pull funding for some vaccines being developed to fight respiratory viruses like COVID-19 and the flu.