Joe Rogan, Peter Hotez, and Elon Musk.Louis Grasse/PxImages/Icon Sportswire via Getty Images; AP Photo/John Mone; Chesnot/Getty Images A vaccine scientist says it's been "overwhelming" getting dogpiled on Twitter by its loudest voices. Peter Hotez said he's used to getting attacks from anti-vaccine lobbyists. But the attacks are now coming from Joe Rogan and Elon Musk, Twitter's most influential users. Vaccine scientist Peter Hotez says it's been "overwhelming" getting tag-teamed on Twitter by some of the platform's most influential voices.