The White House has tapped Jim O’Neill, a top deputy to Health and Human Services Secretary Robert F. Kennedy Jr., to serve as acting director of the Centers for Disease Control and Prevention (CDC) following a leadership shake-up over vaccine policy.

O’Neill, currently the deputy secretary of HHS, will reportedly step in after former CDC Director Susan Monarez’s ouster amid clashes with Kennedy over his push to reshape federal vaccine policy.

Monarez’s departure, followed by the resignations of Dr. Debra Houry, Dr. Demetre Daskalakis and Dr. Daniel Jernigan, deepens a leadership vacuum at the $9.2 billion agency as lawmakers demand oversight and warn that Health and Human Services Secretary Kennedy’s reshaped vaccine panel lacks credibility ahead of its September meeting.

O’Neill is a longtime libertarian-leaning health policy figure who served as principal associate deputy secretary at the Department of Health and Human Services during the George W. Bush administration. A close ally of venture capitalist Peter Thiel, O’Neill has been an advocate of loosening regulations at the Food and Drug Administration.

This is a breaking news article. Updates to follow.

This article includes reporting by The Associated Press.

Update 8/28/25, 5:33 p.m. ET: This article has been updated with additional information.

Jim O’Neill is shown being sworn in as the Deputy Secretary of Health and Human Services by Secretary Robert F. Kennedy Jr. on June 9, 2025.

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