In the Sept. 4 hearing, Kennedy said that Operation Warp Speed was “genius” because it “it got the vaccine to market that was perfectly matched to the virus at that time, when it was badly needed because there was low natural immunity and or people getting very badly injured by COVID.”

The Trump administration is urging public health agencies to prioritize investigations of vaccine injuries, prescription drug use and autism's causes.

Republicans signaled growing concerns over Kennedy’s changes to vaccine policy during his appearance before a Senate committee.