Donald Trump may create a committee on autism, his transition team said Tuesday, after vaccine skeptic Robert F. Kennedy Jr. said Trump had asked him to lead a panel on immunization safety in a meeting at Trump Tower in New York. The Trump team said the president-elect had “enjoyed his discussion” with Kennedy but had made no decisions on the matter.

Kennedy, son of the late U.S. senator, attorney general, and presidential candidate Robert F. Kennedy, has sought to link childhood vaccinations to autism, focusing on the preservative thimerosal, which contains mercury and was once widely used in vaccines. There is no such link, according to a broad scientific consensus. The U.S. Food and Drug Administration, for example, has said “there is no convincing evidence of harm caused by the small doses of thimerosal preservative in influenza vaccines.”

Here are a few things Kennedy has written, said, and done about vaccines over the years.

‘Let the Science Speak’

In 2015, before a vote on immunization requirements for Oregon’s schools, Kennedy invited Oregon state senators to a private screening of Trace Amounts, a documentary about the alleged dangers of thimerosal. Later, at a screening of the film in Sacramento, California, he called the use of vaccines “a holocaust” and said, “They get the shot, that night they have a fever of 103, they go to sleep, and three months later their brain is gone.” In 2014, he published Thimerosal: Let the Science Speak. The Evidence Supporting the Immediate Removal of Mercury—a Known Neurotoxin—from Vaccines.

‘Deadly Immunity’

In 2011, Salon.com, a liberal online news site, took an unusual step: It retracted “Deadly Immunity,” a story by Kennedy it had published six years earlier with Rolling Stone magazine, in which Kennedy sought to link thimerosal with autism. In a note on the site, Kerry Lauerman, then editor in chief, explained his decision:

In the days after running “Deadly Immunity,” we amended the story with five corrections (which can still be found logged here) that went far in undermining Kennedy’s exposé. At the time, we felt that correcting the piece — and keeping it on the site, in the spirit of transparency — was the best way to operate. But subsequent critics, including most recently, Seth Mnookin in his book “The Panic Virus,” further eroded any faith we had in the story’s value. We’ve grown to believe the best reader service is to delete the piece entirely.