Former Centers for Disease Control and Prevention Director Susan Monarez is appearing before the Senate Committee on Health, Education, Labor and Pensions on Wednesday for her first public appearance since she was pushed out of her position leading the nation’s public health agency.
Republican Sen. Bill Cassidy, the panel’s chair and a doctor from Louisiana who was one of the key votes to confirm Health and Human Services Secretary Robert F. Kennedy Jr., said he was focused on learning what led to the abrupt firing of Monarez just weeks after her confirmation.
“Part of our responsibility today is to ask ourselves, if someone is fired 29 days after every Republican votes for her, the Senate confirms her, the secretary said in her swearing in that she has ‘unimpeachable scientific credentials’ and the president called her an incredible mother and dedicated public servant — like what happened? Did we fail? Was there something we should have done differently?” Cassidy said.
Monarez, in her opening statement, gave a detailed timeline on the chain of events that she said led to her ouster.
“Since my removal, several explanations have been offered: that I told the secretary I would resign, that I was not aligned with administration priorities, or that I was untrustworthy. None of those reflect what actually happened,” Monarez said.
Monarez said there was a meeting in which she says Kennedy told her to preemptively accept recommendations from a CDC vaccine advisory panel and to fire career officials overseeing vaccine policy.
“I would not commit to that, and I believe it is the true reason I was fired,” Monarez said.
She also claimed that Kennedy spoke to the White House “several times” prior to the meeting about firing her.
“I could have kept the office and the title. But I would have lost the one thing that cannot be replaced: my integrity,” Monarez said.
Former Centers for Disease Control and Prevention Director Susan Monarez arrives to testify before a Senate Health, Education, Labor and Pensions Committee hearing on Capitol Hill in Washington, September 17, 2025.
Elizabeth Frantz/Reuters
Kennedy, in his hearing before the Senate Finance Committee on Sept. 4, disputed Monarez’s version of events, which she first shared that same day in an op-ed published by the Wall Street Journal.
“Did you, in fact, do what Director Monarez has said you did, which is tell her, ‘Just go along with vaccine recommendations, even if you didn’t think such recommendations aligned with scientific evidence?'” Sen. Ron Wyden, D-Ore., asked Kennedy.
“No, I did not,” Kennedy replied.
In a fiery exchange with Democratic Sen. Elizabeth Warren, Warren noted that Kennedy had just a month before described Monarez as “unimpeachable” after she was confirmed.
“I told her that she had to resign because I asked her, ‘Are you a trustworthy person?’ And she said, ‘No,'” Kennedy replied. “If you had an employee who told you they weren’t trustworthy, would you ask them to resign, Senator?”
Monarez is being joined at Wednesday’s hearing by Deb Houry, former chief medical officer and deputy director for program and science at the CDC, who was one of four top CDC officials who resigned in protest after Monarez was ousted.
The high-profile departures raised alarm over Kennedy’s vaccine policy agenda, which the public health officials said they were being asked to endorse without adequate science.
Sen. Cassidy told Monarez and Houry on Wednesday that “the onus is upon you to prove that the criticisms leveled by the secretary are not true.”
Cassidy’s decision to pursue oversight of the CDC turmoil signifies a new, firmer era for his relationship with Kennedy — a shift was on full display during Kennedy’s own hearing before the Senate earlier this month.
The senator accused Kennedy of undermining President Donald Trump’s legacy on Operation Warp Speed, the government effort that fast-tracked the COVID vaccine, and told him recent FDA changes to COVID vaccines were “denying” people access.
Democratic Sen. Lisa Blunt Rochester, who sits on the HELP Committee and has called for Kennedy to step down, said Cassidy’s decision to call Monarez to testify showed a continued “weakening” of support for the secretary.
“I think Secretary Kennedy’s actions at the Finance Committee left a lot of not just Democrats, but Republicans very unsettled,” Blunt Rochester told ABC News in an interview.
“The fact that a Republican is chairing the committee and called for her to come is a positive step, and maybe shows there is some weakening. But the reality is, you know, Secretary Kennedy needs to go — whether that is he’s fired, whether he quits, he is unsafe for America,” she said.
Health and Human Services Secretary Robert F. Kennedy Jr is interviewed outside of the White House West Wing, September 9, 2025 in Washington.
Saul Loeb/AFP via Getty Images
During the Senate Finance Committee hearing on Sept. 4, Cassidy was joined by two other Republicans on the committee — Sens. John Barrasso of Wyoming, the second most powerful GOP senator, and Thom Tillis of North Carolina, who announced earlier this year he was not running for reelection — in expressing concern over Kennedy’s handling of vaccines and the CDC.
Other high-level Republicans have also voiced criticism, including Senate Majority Leader John Thune, who said Kennedy had to “take responsibility” for firing Monarez just four weeks after the Senate confirmed her. Republican Sen. Susan Collins of Maine said she didn’t see any “justification” for the termination.
Republican Sen. John Kennedy, Cassidy’s counterpart in Louisiana, called Kennedy’s handling of the CDC a “multiple vehicle pileup.”
Monarez, who HHS publicly announced was “no longer director” on a Wednesday afternoon in late August, drew widespread attention when she refused to leave her post, asking Trump to weigh in and fire her directly if he agreed with his HHS secretary. She said she was pushed out because she wouldn’t agree to rubber-stamp Kennedy’s agenda or fire high-ranking scientists.
The move put a spotlight on Kennedy’s vaccine policy changes, which have ramped up in recent weeks. Kennedy canceled around $500 million in contracts for mRNA vaccines, changed the recommendations for healthy children and pregnant women to receive COVID-19 vaccinations and, through the FDA, oversaw the narrowing of approval for the updated COVID shots this fall only to people over 65, or younger Americans with underlying conditions.
Later this month, a CDC committee will meet to discuss vaccine recommendations more broadly, including the measles, mumps, rubella, varicella (MMRV) vaccine, and Respiratory Syncytial Virus (RSV).
Kennedy has replaced all of the members of the committee with handpicked people, some of whom have expressed criticism of vaccines. Asked by ABC News if he plans to limit access to any of those vaccines, Kennedy said the committee would decide after a “real gold standard scientific review.”
“Parents deserve a CDC they can trust to put children above politics, evidence above ideology and facts above fear,” Monarez wrote in the WSJ on Sept. 4.
“I was fired for holding that line,” she wrote.
Kennedy stood by the recent shakeups at CDC, saying they were “absolutely necessary adjustments to restore the agency to its role as the world’s gold standard public health agency with a central mission of protecting Americans from infectious disease.”