Not one to shy away from conspiracy theories, Donald Trump on Tuesday waded deeper into the controversy surrounding the hotly-debated anti-vaccination movement, appointing noted vaccine critic Robert F. Kennedy Jr. to chair a commission on vaccine safety.

“President-Elect Trump has some doubts about the current vaccine policies and he has questions about it,” Kennedy told reporters Tuesday shortly after meeting with Trump at the real-estate mogul’s gilded tower in Midtown Manhattan. The president-elect had asked him to “chair a commission on vaccination safety and scientific integrity,” Kennedy said—and he agreed. “Everybody ought to be able to be assured that the vaccines that we have—he’s very pro-vaccine, as am I—but they’re as safe as they possibly can be.”

The Trump transition office released a statement later Tuesday, saying that Trump is “exploring the possibility of forming a committee on Autism, which affects so many families“ but “no decisions have been made at this time.”

Both Kennedy and Trump have weathered criticism in the past for a number of controversial comments about vaccines and the widely debunked theory that they are linked to autism. Kennedy, who wrote a book proselytizing the link titled Thimerosal: Let the Science Speak, incited fierce backlash last year when he compared the rise of autism to a “holocaust”—a characterization for which he later apologized.

Trump, too, has suggested a causal link between childhood vaccination and autism, offering no evidence to support the claim. On Twitter in 2012, the billionaire New Yorker condemned “massive doses” of vaccinations and called on doctors to “go back to single, spread out shots!” Trump presented a similar argument two years later. “Healthy young child goes to doctor, gets pumped with massive shot of many vaccines, doesn't feel good and changes - AUTISM. Many such cases!” he wrote.

The controversial issue came up in a Republican-primary debate in September, during which Trump asserted that he is “totally in favor of vaccines,” but once again advocated for “smaller doses over a longer period of time” before adding, “we’ve had so many instances, people that work for me. . . . [in which] a child, a beautiful child went to have the vaccine, and came back and a week later had a tremendous fever, got very, very sick, now is autistic.”

There is no link between vaccines and autism, according to the Centers for Disease Control. The C.D.C. notes that there have been nine C.D.C.-funded or conducted studies since 2003 on thimerosal-containing vaccines, all of which found no link to autism spectrum disorder.

This story has been updated.