Jim O’Neill, who had been serving as acting director of the Centers for Disease Control and Prevention (CDC) and was deputy secretary at the Department of Health and Human Services (HHS), has left his position. According to a report from STAT News, confirmed by HHS spokesman Andrew Nixon, O’Neill’s last day was Friday. President Donald Trump has not yet named a replacement for O’Neill or announced a new leader for the CDC. Politico first reported on O’Neill’s resignation.
Currently, Ralph Abraham is the most senior official at the CDC, serving as principal deputy director since December after being sworn in by HHS Secretary Robert F. Kennedy Jr. Abraham has deferred questions about who will lead the CDC to the White House, according to STAT.
O’Neill’s departure follows a period of instability at the agency. Former CDC Director Susan Monarez was dismissed in August 2025 after less than a month in her role. After her termination, Monarez stated that Kennedy had asked her to “preapprove” certain recommendations made by the CDC’s vaccines advisory panel. She said she was forced out after refusing this request.
During a Senate hearing in September 2025, Monarez testified that Kennedy made accusations against CDC staff: “He said that CDC employees were killing children, and they don’t care,” Monarez told Sen. Maggie Hassan (D-NH). Kennedy denied these claims and said Monarez was not truthful about her dismissal.
The leadership changes come during ongoing debates over public health policies related to vaccines. Recently, the Food and Drug Administration (FDA) declined to review Moderna’s mRNA-based flu vaccine because it did not meet specific trial recommendations. This decision drew criticism from industry representatives; however, HHS supported the FDA’s stance, with an unnamed official saying Moderna should acknowledge its failure to follow recommendations.
