Jim O’Neill was deputy secretary at the Department of Health and Human Services and also acting director of the CDC after the abrupt ouster of Susan Monarez in August 2025.
Jim O’Neill, deputy secretary at the Department of Health and Human Services, has left the agency. That leaves the CDC, where he had been acting director, without a leader—again.
O’Neill’s last day at work was Friday, according to a STAT News report on Feb. 15, which confirmed his exit with HHS spokesman Andrew Nixon. President Donald Trump hasn’t yet named a replacement for O’Neill, nor has he publicly identified someone to lead the CDC. Politico first broke the news of O’Neill’s resignation.
Currently, the most senior official at the CDC is its principal deputy director, Ralph Abraham, whom Health and Human Services Secretary Robert F. Kennedy Jr. swore into the post last December. On the matter of who will take leadership of the CDC—either temporarily as acting director or more permanently as the agency’s actual director—Abraham has deferred to the White House, according to STAT.
O’Neill’s exit comes after former CDC Director Susan Monarez was fired in August 2025 after just 28 days on the job. In the weeks that followed her termination, Monarez revealed that she had been asked by Kennedy to “preapprove” certain recommendations by the CDC’s vaccines advisory panel. After she refused, she was forced out.
In a Senate hearing in September last year, Monarez also claimed that Kennedy made certain “assertions” about the CDC.
“He said that CDC employees were killing children, and they don’t care,” Monarez said during questioning from Sen. Maggie Hassan (D-NH). Kennedy, for his part, said that Monarez was lying about the circumstances of her termination.
The leadership chaos at the U.S.’s top public health agency comes amid continued controversial public health policies, especially around vaccines. Most recently, for instance, the FDA refused to review Moderna’s mRNA-based flu shot, saying the company had failed to abide by certain recommendations in its pivotal trial. Amid blowback and criticism from the industry, the HHS backed the FDA, with an unnamed official saying that Moderna should “show some humility and that, yes, we didn’t follow your recommendation.”
