Health and Human Services Secretary Robert F. Kennedy Jr. testifies at a Senate hearing in Washington, DC, on Sept. 4, 2025.

Three weeks after she was fired from Centers for Disease Control and Prevention after clashing over vaccine policy with Health Secretary Robert F. Kennedy Jr., former director Susan Monarez will have her turn at the microphone at a highly anticipated Sept. 17 Senate hearing.

It's Monarez’s first public appearance since her ouster late last month by the Trump administration for what her lawyers described as her refusal to “rubber-stamp unscientific, reckless directives and fire dedicated health experts.”

Kennedy accused Monarez, who holds a Ph.D in microbiology and immunology, of lying about the circumstances of her dismissal during a contentious Sept. 4 Senate hearing where he faced tough questions from Republicans and Democrats.

Monarez said she was let go because she refused to "preapprove the recommendations of a vaccine advisory panel newly filled with people who have publicly expressed antivaccine rhetoric.” Kennedy said Monarez − whom he had previously praised for her "unimpeachable scientific credentials" − was ousted because she was "not trustworthy."

In the end, Monarez's tenure at the CDC was shorter than her confirmation process. Just 29 days after she was confirmed by the Senate, she was ousted by Kennedy and President Donald Trump's White House. Three top CDC officials resigned after Monarez was fired. One of them, former CDC Chief Medical Officer Debra Houry, is also expected to testify next to Monarez.

Meanwhile, more than 1,000 current and former Health and Human Services officials have called for Kennedy to step down from his position saying he was “endangering the nation’s health by spreading inaccurate health information.”

Sen. Bill Cassidy, a physician and the Republican-led leader of the Senate Committee on Health, Education, Labor and Pensions, said the hearing will center around recent events at the CDC.

Kennedy is a vaccine skeptic with no medical background, who has promoted a controversial and unfounded theory that links vaccines to autism.

In June, Kennedy removed all 17 members of the CDC's expert vaccine panel and filled many of the positions with people who have been vaccine skeptics or questioned COVID-19 vaccine mandates. The newly constituted vaccine panel is scheduled to begin meeting the day after Monarez testifies on Sept. 18-19.

In an opinion article for the Wall Street Journal on Sept. 4, Monarez wrote that she was “told to preapprove the recommendations of a vaccine advisory panel newly filled with people who have publicly expressed antivaccine rhetoric.”

“It is imperative that the panel’s recommendations aren’t rubber-stamped but instead are rigorously and scientifically reviewed before being accepted or rejected,” she added.

Kennedy has also questioned the safety and efficacy of mRNA vaccines, the technology that was used to develop the most effective COVID vaccines. In August, the Department of Health and Human Services shut down 22 federally funded mRNA vaccine programs, representing $500 million in strategic biomedical research. Kennedy also terminated the emergency-use authorizations for COVID-19 vaccines.

Under the updated approvals, only those over 65 and younger people with underlying health conditions would be recommended for the COVID-19 vaccine. At the same time, it is available to anyone who wants to get it in consultation with their doctor.

During an appearance before the Senate Finance committee on the same day Monarez published her op-ed, Kennedy accused her of lying.

That hearing also drew heated exchanges on the turmoil at the CDC, and in particular about Monarez’s dismissal. Kennedy accused Monarez of fudging the reason she was dismissed.

"I told her that she had to resign because I asked her, 'Are you a trustworthy person?' And she said no," Kennedy said.

Swapna Venugopal Ramaswamy is a White House Correspondent for USA TODAY. You can follow her on X @SwapnaVenugopal

This article originally appeared on USA TODAY: RFK Jr. got her fired. Now ex-CDC head Susan Monarez will testify before Senate

Reporting by Swapna Venugopal Ramaswamy, USA TODAY / USA TODAY

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