Moderna Inc. shares are selling off Wednesday, after the Trump administration took aim at the science behind the biotechnology company’s vaccines and said it would cancel some contracts and stop funding mRNA drug development.

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.