The Senate on Tuesday confirmed Susan Monarez to lead the Centers for Disease Control and Prevention (CDC), putting a longtime government scientist at the helm of an agency being upended by Health and Human Services (HHS) Secretary Robert F. Kennedy Jr.  

Monarez, 50, is President Trump’s second pick for the job. She was confirmed on a largely party-line vote, 51-47.

The CDC has not had a leader since March, when Monarez stepped down as acting director because she was nominated to be director. She is the first nominee for CDC director to require Senate confirmation. 

Monarez will take the helm of an agency under fire.  

The Trump administration is looking to slash its budget by almost half in 2026, and hundreds of staff have been cut. Meanwhile, doctors and public health experts have accused Kennedy of undermining the agency’s credibility by changing vaccine recommendations and firing all members of a vaccine advisory panel. 

In the absence of a director, Kennedy fired all 17 members of the Advisory Committee on Immunization Practices (ACIP) and replaced them with his own handpicked members. The CDC director must sign off on ACIP recommendations for them to become official agency policy, but Kennedy has taken on the role himself without a director in place. 

Kennedy’s ACIP last month voted to remove the preservative thimerosal from flu vaccines, despite numerous studies showing it is safe, if rarely used anymore. Kennedy signed the recommendation last week, but he has yet to sign one from the same meeting recommending everyone get a flu shot.  

He also bypassed traditional agency pathways when he unilaterally announced HHS would no longer recommend COVID-19 vaccines for healthy pregnant women and healthy children. 

Unlike other Trump health nominees, Monarez is not known as a controversial flamethrower. She has worked in the federal government for nearly 20 years across multiple offices but had not worked for the CDC prior to Trump tapping her as the agency’s acting head shortly after beginning his second term. 

Prior to her role at CDC, she served as deputy director at the Advanced Research Projects Agency for Health. Before entering government work, she was a science and technology policy fellow with the American Association for the Advancement of Science. 

Trump chose Monarez to lead the agency after his first choice, former Florida Rep. Dave Weldon (R), failed to gain enough support among Senate Republicans. Weldon was heavily scrutinized for promoting a debunked link between vaccines and autism.  

During her confirmation hearing, Monarez told Democrats that “vaccines save lives” and said there was no evidence vaccines cause autism. 

But she walked a fine line and was careful not to directly contradict her would-be boss, despite prodding by Democratic senators. She advanced through the Senate Health, Education, Labor and Pensions (HELP) Committee on a party-line vote.  

“In my view, we need a CDC director who will defend science, protect public health, repudiate Secretary Kennedy’s dangerous conspiracy theories about safe and effective vaccines that have saved over the years millions of lives,” Sen. Bernie Sanders (I-Vt.), the ranking member of the HELP Committee, said before he voted against advancing her nomination to the floor. 

“Unfortunately, after reviewing her record, I do not believe that Dr. Monarez sees that person,” Sanders said.  

In supporting Monarez’s nomination, HELP Committee Chair Bill Cassidy (R-La.) said the country “needs a CDC director who makes decisions rooted in science, a leader who will reform the agency and work to restore public trust in health institutions.”