The White House has named Deputy Secretary of Health and Human Services Jim O’Neill as acting director of the U.S. Centers for Disease Control and Prevention (CDC). The decision follows the dismissal of Susan Monarez, who held the position for approximately a month.

O’Neill’s appointment comes amid significant upheaval at the CDC, including recent high-profile resignations. Agency employees recently gathered outside the CDC’s Atlanta headquarters to honor departing officials such as Dr. Debra Houry, Dr. Demetre Daskalakis, Dr. Daniel Jernigan, and Dr. Jennifer Layden.

HHS Secretary Robert F. Kennedy Jr. highlighted O’Neill’s background in technology and government, stating he is “ideally suited to transition HHS into a technological innovation powerhouse.” O’Neill, who joined HHS in June after years as a Silicon Valley-based investor, previously worked with the Thiel Foundation and the Thiel Fellowship. He also served in the George W. Bush administration, where he oversaw food regulation and emergency response initiatives.

O’Neill’s lack of medical or infectious disease expertise contrasts with Monarez, who was seen by some as a potential counterbalance to Kennedy’s anti-vaccine stance. During the COVID-19 pandemic, O’Neill publicly supported unproven treatments like ivermectin and hydroxychloroquine, as well as conspiracy theories about the virus’s origins.

The CDC is set to convene vaccine advisers in the coming weeks, with O’Neill expected to play a central role in shaping new guidelines for updated COVID-19 vaccines.