"This is one of the greatest scientific accomplishments in history. It will save millions of lives and soon end the pandemic once and for all," Trump said at the time in a speech delivered from the Oval Office.

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."

Robert F. Kennedy Jr. has announced that his department will end funding for a series of mRNA-based vaccines aimed at preventing major respiratory illnesses.