| When Health Secretary Robert F. Kennedy Jr. was asked during a Senate hearing last week who at the CDC was briefing him, he cited an unexpected official: William Thompson. Thompson may not be a household name or a senior official at the public health agency that Kennedy oversees. But he’s a celebrity of sorts among some anti-vaccine activists. To them, he’s a whistleblower who breathed life into their theory that vaccines cause autism, which has been widely debunked. Thompson was a co-author of a 2004 CDC study that analyzed what ages children with and without autism got their first vaccine for measles, mumps and rubella, known as MMR. The study found no association. But more than a decade later, Thompson got attention when his voice appeared in the controversial documentary Vaxxed: From Cover-Up to Catastrophe. The film, directed by the anti-vaccine activist Andrew Wakefield, features a secret recording of Thompson claiming that the CDC left out data from the study that would have shown African American boys had a higher incidence of autism after getting an MMR vaccine. Kennedy cited the study and Thompson during his Senate hearing on Thursday, saying such omissions happen “all the time.” “We’re being lied to by these agencies and we’re going to change that right now,” Kennedy said. Thompson could not be reached for comment. He released a statement back in 2014 after he realized his conversations had been secretly recorded. In the statement, Thompson said he’d never suggest that parents avoid vaccinating children of any race and that “I believe vaccines have saved and continue to save countless lives.” He said, however, that he was concerned about the decision to omit some findings in the study. In his statement, Thompson said that he’s worked at the agency since 1998. Over the ensuing years, he’s kept a low profile. He’s still employed at the CDC and has spent time working on teams that focus on prevention of HIV. Kennedy’s mention of him at last week’s Senate hearing is a reminder of the unusual figures who have the ear of the country’s top health official. In his resignation letter posted last month on social media, Demetre Daskalakis, former director of the CDC’s National Center for Immunization and Respiratory Diseases, said no subject matter expert from his center had briefed Kennedy on key diseases like measles and bird flu since he took over HHS almost seven months ago. On Friday, after the senate hearing, Daskalakis posted that the briefer Kennedy cited “does not work in the safety office or the immunization center,” and isn’t “familiar with data or analysis on any of the diseases covered by the CDC immunization center.” What Thompson and Kennedy have discussed is unclear. An HHS spokesman did not respond to a request for comment. Kennedy added that Thompson was just one of the CDC staffers who are briefing him. But the subject that once put Thompson in the spotlight isn’t going away anytime soon. Despite decades of research that hasn’t identified just one cause of autism, Kennedy has promised the US government will have answers to the question this month. Last week, HHS pushed back on a report that it would link Tylenol to autism. — Gerry Smith and Jessica Nix. | 
