HHS Secretary Robert F. Kennedy Jr. appointed his deputy, Jim O’Neill, as acting CDC director after President Trump fired Susan Monarez less than a month into her tenure for resisting Kennedy’s vaccine policy changes, deepening turmoil at the agency.
“Together, we will rebuild this institution into what it was always meant to be: a guardian of America’s health and security,” Kennedy wrote on Thursday in a memo to CDC staff seen by Reuters. “To help advance this mission, I am pleased to announce that Deputy Secretary of Health and Human Services Jim O’Neill is now also serving as Acting Director of the CDC.”
The firing of Monarez sparked the resignations of four senior CDC officials. Additionally, the White House proposed slashing nearly $3.6 billion from the CDC’s budget, leaving $4 billion for 2026, while Kennedy’s layoff plan resulted in the dismissal of 2,400 staff members, with about 700 later rehired.
Before becoming Kennedy’s deputy, O’Neill worked as a health policy adviser with connections to multiple healthcare firms. He previously ran Peter Thiel’s Mithril Capital from 2012 to 2019 and also served as CEO of the Thiel Foundation and managing director at Thiel Capital.
Public health is a noble calling. When it is driven by transparent data and rigorous science, it earns public trust and keeps the world safe.
The beating heart of public health in America is CDC. During the previous administration, CDC lost public trust by manipulating health…
— Deputy Secretary Jim O’Neill (@HHS_Jim) August 29, 2025
