The White House appoints Jim O'Neill, a key advisor to RFK Jr., as acting director of the CDC following Monarez's dismissal

The White House selected Jim O'Neill, deputy secretary of the Department of Health and Human Services (HHS), on Thursday to take over as acting director of the Centers for Disease Control and Prevention (CDC), according to reports from the Washington Post.

The appointment comes a day after the firing of former director Susan Monarez and the subsequent resignations of several top agency officials amid a clash over vaccination policies.

O'Neill, a key adviser to Robert F. Kennedy Jr., the secretary of Health and Human Services, will continue to oversee HHS operations while temporarily heading the CDC.

For his part, O'Neill, who has previous experience at HHS during the Bush administration and in the biotech sector, was confirmed as undersecretary in June of this year and assumed the post on June 9.

White House decision on Monarez

Earlier, the White House insisted that President Donald Trump fired Susan Monarez as CDC director after she refused to resign under pressure.

Monarez, a scientist with decades of experience in the federal government, had been confirmed by the Senate just over a month earlier on July 31, becoming the first CDC director to undergo that legislative process following a law passed during the COVID-19 pandemic.

White House spokeswoman Karoline Leavitt defended the decision during a press conference Thursday, stating that “the president fired her, which he has every right to do." She further emphasized that Trump possesses “the authority to fire those who are not aligned with his mission."

According to Leavitt, Monarez was not aligned with the agenda pushed by the Trump administration. The departure comes amid growing tensions at the CDC, which has faced massive staff cuts, budget reductions and a shooting at its Atlanta headquarters, where an attacker killed a police officer.

Controversy with the Department of Health

The conflict arose over disagreements over vaccination policies, according to reports from The New York Times. The outlet notes that sources familiar with the events indicated that Kennedy pressured Monarez to support changes to vaccine recommendations, including revoking authorizations for certain groups, and to fire top CDC officials. Monarez refused, arguing the need to consult experts and prioritize scientific evidence, prompting Kennedy to demand her resignation on Monday. When she refused to resign, the White House stepped in to formalize her dismissal, the media outlet reviewed.

Monarez's defense

Monarez's lawyers, Mark Zaid and Abbe David Lowell, issued combative statements rejecting the validity of the firing.

In an initial statement, they asserted that “contrary to govt statements, Dr. Monarez has neither resigned nor yet been fired.” Later, Zaid specified that, “As a presidential appointee, senate confirmed officer, only the president himself can fire her.”

Vaccines and autism

During her brief tenure, she publicly defended vaccines at her confirmation hearing, asserting that she had seen no evidence of a causal link to autism, a position that contrasted with Kennedy's view.

RFK Jr. on problems at CDC

The health secretary, in an interview with Fox News this Thursday morning, sharply criticized the CDC, asserting that the agency "is in trouble and we are fixing it and it may be that some people should not be working there anymore."

Kennedy alleged that the CDC took a "wrong" approach during the COVID-19 pandemic on issues such as social distancing, use of masks and school closures, which caused “much harm to the American people.”

The health secretary noted, "We need to look at the priorities of the agency if there's really a deeply embedded – I would say – malaise at the agency, and we need strong leadership that will go in there and that will be able to execute on President Trump's broad ambitions to restore this agency to gold standard science and to what it was when we were growing up, which was the most respected health agency in the world."

Monarez's departure and other resignations

Monarez's departure brought subsequent resignations: Chief Medical Officer Debra Houry, National Center for Immunization and Respiratory Diseases Director Demetre Daskalakis, National Center for Emerging and Zoonotic Infectious Diseases Director Daniel Jernigan, and Office of Public Health Data Director Jennifer Layden have left CDC without leadership.