ATLANTA — William Thompson, a senior scientist at the Centers for Disease Control and Prevention (CDC), objected to a proposed work assignment and copied HHS Secretary Robert F. Kennedy Jr. on correspondence with CDC leadership regarding access to original data from a 2004 autism study. Emails released by the Senate Committee on Health, Education, Labor, and Pensions show Thompson stated he was working on behalf of the Secretary's interests.

On May 29, 2025, Thompson, who works in the CDC's Division of Viral Hepatitis and co-authored the 2004 study, emailed a branch chief at the CDC's National Center on Birth Defects and Developmental Disabilities requesting the original data. Suzanne Gilboa, acting director of the center, stated in an email that data for the 2004 paper were compiled in 2014 in response to a previous request involving Brian Hooker of Children's Health Defense. Gilboa also stated that original data for the study were linked to school vaccine records solely for the study.

Thompson replied that he was interested in whether the original data sources exist. He wrote that he did all the analyses for the 2004 study and received a cleaned dataset with cases and controls already matched and birth certificate data already merged. He wrote that HHS would like access to the original data sources to merge the data, using those datasets, to test additional hypotheses. Gilboa responded that the CDC did not have the original source data for the study. On July 10, 2025, Kennedy responded to the email thread regarding the data request.

On June 25, 2026, Debra Houry, the former CDC chief medical officer, sent a proposed scope of work for Thompson to Stuart Burns, a former Republican congressional aide working in the CDC director's office. The proposed scope involved Thompson working 50% of his time at the National Center on Birth Defects and Developmental Disabilities and 50% for his home division. Houry stated in an email that she was not involved in conversations with Thompson or HHS about the position.

Thompson forwarded the scope of work to Brooke Hoots, a CDC employee in the Division of Viral Hepatitis, and copied Kennedy. Thompson wrote, "NCBDDD put together this statement of work without input from me, Stuart Burns ... or Secretary Kennedy." He added, "This SOW has nothing to do with the tasks that Secretary Kennedy has assigned me to carry out." Thompson concluded his statement describing the document as, "It is actually one of the most absurd SOWs I have ever seen."

Thompson asked for his detail to be delayed until a new CDC Director was appointed. Heather Flick Melanson, Kennedy's chief of staff at HHS, replied confirming plans to delay his detail. Melanson wrote that Thompson should continue to perform work for the Immediate Office of the Secretary as requested. Houry wrote to Burns and CDC chief of staff Matthew Buzzelli about Thompson's response. Houry wrote that she was disappointed in Thompson's behavior related to his detail, calling it unprofessional. Houry reiterated that she was not part of the initial discussions about the scope of the detail and wrote, "I do not appreciate Bill including the Secretary, HHS OGC, and HHS Chief of Staff on his response about the scope of the detail." Houry also wrote, "This felt like a direct attack on me without first providing any input about the draft scope."