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."

While anti-vaxxers are thrilled, experts warn that defunding mRNA development takes away our already-proven best weapon against future pandemics.

U.S. Health Secretary Robert F. Kennedy Jr. incorrectly argued mRNA vaccines are ineffective to justify the Department of Health and Human Service's recent decision to cancel $500 million in government-funded research projects to develop new vaccines using the technology.