Kennedy has been criticized for making false medical claims. He has also vowed to purge the U.S. Food and Drug Administration.

Shares of major U.S. drugmakers fell on Friday after President-elect Donald Trump picked anti-vaccine activist Robert F. Kennedy Jr. to head the Department of Health and Human Services, the top U.S. health agency.

President-elect Donald Trump said he’s tapping Robert F. Kennedy Jr. to run the Department of Health and Human Services, a move that would elevate a prominent vaccine skeptic and pharmaceutical industry critic to a top role on federal health policy.