Donald Trump asked Robert Kennedy Jr., a proponent of a widely discredited theory that vaccines cause autism, to chair a new commission on vaccine safety and scientific integrity, according to Kennedy.

The stunning move would contradict established science, medicine and the government’s position on the issue. It comes after Trump – who has long been critical of vaccines – met at Trump Tower with Kennedy, who has spearheaded efforts to roll back child vaccination laws.

Trump transition officials did not respond to requests for comment on the commission.

Speaking to reporters in the lobby of Trump Tower in New York, on Tuesday, Kennedy said that Trump called him to request the meeting, and he accepted the position on the new commission. It is unclear exactly what role the commission would play.

“President-elect Trump has some doubts about the current vaccine policies, and he has questions about it,” Kennedy said. “His opinion doesn’t matter, but the science does matter, and we ought to be reading the science, and we ought to be debating the science.”

The announcement was met with alarm from health professionals who say that putting a proponent of a conspiracy theory in a position of authority on this issue is dangerous.

“That’s very frightening, it’s difficult to imagine anyone less qualified to serve on a commission for vaccine science,” said Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, and president of the Sabin Vaccine Institute, a nonprofit that works to control, treat and eliminate vaccine-preventable and neglected tropical diseases.

“The science is clear: massive evidence showing no link between vaccines and autism, and as both a scientist who develops vaccines for poverty related neglected diseases and the father of an adult daughter with autism, there’s not even any plausibility for a link,” Hotez continued. “Autism is a genetic condition.”

“Our nation’s public health will suffer if this nascent neo-antivaxxer movement is not stopped immediately,” he added.

Trump notably expressed support for the theory at a Republican presidential debate in 2015.

“You take this little beautiful baby, and you pump …” he said of vaccinating children. “We had so many instances, people that work for me, just the other day, 2 years old, a beautiful child, went to have the vaccine and came back and a week later got a tremendous fever, got very, very sick, now is autistic.”