When COVID-19 cases were surging, Dr. David Wohl saw patients "hungry for air" fill UNC hospital wards. What most saved lives, he said, were vaccines developed with unprecedented speed using mRNA technologies.

This was one in a continuing line of moves that have put Kennedy's vaccine skepticism into public policy, though scientists say the vaccines are safe.

In justifying the government's termination of $500 million in funding for mRNA vaccine projects, Health and Human Services Secretary Robert F. Kennedy Jr. falsely claimed mRNA vaccines "fail to protect effectively" against COVID-19 and suggested they are unsafe.