Mr. Kennedy, on the other hand, is a vaccine cynic, failing to accept studies that refute his beliefs. He claims that the measles-mumps-rubella vaccine causes autism despite more than a dozen studies performed in seven countries on three continents involving thousands of children showing that it doesn’t.

In May 2021, just six months after the rollout of the Covid vaccine, Robert F. Kennedy Junior tried to stop all coronavirus vaccinations in the U.S., the New York Times reports. Sen. Ed Markey joins to discuss that and more.