A top adviser to HHS Secretary Robert F. Kennedy, Jr. was appointed to lead the CDC in an acting capacity on Thursday after Trump's previous appointee, Susan Monarez, was abruptly fired from the position on Wednesday.

Monarez has been the acting CDC director since President Donald Trump took office in January, and was finally confirmed in July.

White House Press Secretary Karoline Leavitt said only that Monarez was not "aligned with the president's vision."

The AP first reported that Jim O'Neill would replace Monarez, even before a formal announcement was made, citing a source close to the administration.

She refuses

Despite being fired and replaced, Monarez is reportedly refusing to leave her post. Dozens of CDC staffers and leaders resigned and/or walked out after she was fired.

“We knew ... if she leaves, we don’t have scientific leadership anymore, ” one of the officials, Dr. Debra Houry, told The Associated Press on Thursday. “We were going to see if she was able to weather the storm. And when she was not, we were done.”

Lawyers trying to help Monarez keep her job said she was fired for standing up for science, whatever that means.

Leavitt also said that Kennedy and Trump are "committed to restoring trust and transparency and credibility to the CDC" and will "make sure that folks that are in positions of leadership there are aligned with that mission."

The agenda

O'Neill was formerly a top aide to George W. Bush during his presidency. He served in several roles, including principal associate deputy secretary.

He criticized pandemic lockdowns and other policies under Trump and former President Joe Biden, many of which have proven to be ineffective over time.

He also pushed during a speech back in 2014 for the FDA to base its approval for drugs solely on whether they are safe, not whether they work or not.

“We should reform FDA so that it’s approving drugs after their sponsors have demonstrated safety and let people start using them at their own risk, but not much risk of safety,” O’Neill said at the time.

This fits into Trump's free-market approach, which looks to give markets and consumers more control rather than regulating everything.

It is unknown whether O'Neill will be appointed to the position permanently, but if he is nominated, it may take some time for him to be confirmed with the way the Senate seems to be slow-walking Trump's nominees.