Monarez: I was Fired for Holding the Line on Scientific Integrity

Susan Monarez, Ph.D.

As many expected, Susan Monarez, Ph.D., who served just 29 days as the first Senate-confirmed CDC director before being dismissed in August 2025, told a Senate committee today that HHS Secretary Robert F. Kennedy Jr. demanded she preapprove all recommendations from his newly appointed vaccine advisory panel.

“He directed me to commit in advance to approving every ACIP recommendation, regardless of the scientific evidence,” Monarez testified during her opening statement before the Senate Health, Education, Labor, and Pensions (HELP) committee. "He also directed me to dismiss career officials responsible for vaccine policy without cause. He said if I was unwilling to do both, I should resign.”

Monarez told the committee that she couldn’t preapprove recommendations from the Advisory Committee on Immunization Practices without reviewing the evidence and that she had no basis to fire scientific experts.

“As I wrote in my September 4 Wall Street Journal Op Ed, I agree with President Trump that we should not hesitate to ask for proof about our vaccines. And I also agree with his most recent comments that vaccines are not controversial because they work. Demanding evidence is exactly what I was doing when I insisted CDC recommendations be based on credible science.”

The hearing became a he-said, she-said debate, with some Republican senators insisting that she wasn’t telling the whole truth about her interactions with Kennedy on the days leading up to her dismissal from the CDC.

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Two weeks ago, Kennedy testified before the Senate Finance Committee, facing questions about his vaccine policy, CDC changes, and his appointment of the new ACIP panel that included vaccine skeptics. He had testified at that hearing that the changes were necessary to restore the public trust. Kennedy even suggested that Monarez was a liar and that she told him she was "untrustworthy.”

At today’s hearing, Monarez said it was Kennedy who had said he could trust her to implement. “I could have stayed silent, agreed to the demands, and no one would have known. What the public would have seen were scientists dismissed without cause and vaccine protections wildly eroded.”

Bill Cassidy, M.D.

Under questioning from Chairman Bill Cassidy, a physician and a Republican from Louisiana, Monarez said she and Kennedy “got into an exchange where I had suggested that I would be open to changing childhood vaccine schedules if the evidence or science were supportive. He responded that there was no science or evidence associated with the childhood vaccine schedule, and he elaborated that the CDC had never collected the science or the data to make it available related to the safety.”

Kennedy has in the past misrepresented how vaccines are studied, saying that vaccines were never tested in controlled clinical trials with a placebo, that vaccines put children at risk, and that some are unnecessary.

At the hearing, Republican senators Roger Marshall of Kansas and Rand Paul of Kentucky defended Kennedy's approach and questioned the necessity of certain vaccines, particularly COVID-19 vaccines for young children. Marshall repeated misinformation that children receive 70 to 80 doses of various vaccines, when in reality it is closer to 30 doses, excluding flu and COVID-19 vaccines.

Paul argued there was insufficient evidence that COVID-19 vaccines reduce hospitalization or death in children under 18, saying the recommendation was based primarily on antibody production rather than clinical outcomes. "The burden should be on you to prove to us that we need to give our six-month-old a COVID vaccine and that we need to give our one-day-old a hepatitis B vaccine," he told Monarez.

Debra Houry, M.D., the former CDC chief medical officer who resigned three weeks ago, corroborated Monarez’s account and described her own concerns about political interference in scientific decisions. She testified that she learned about changes to CDC's COVID vaccine guidance through a social media post rather than through official channels.

“I first learned that the secretary had changed our CDC COVID vaccine guidance on an X social media post," Houry said. "CDC scientists have still not seen the scientific data or justification for this change."

Houry described a pattern of censorship and political control, saying Kennedy's office ordered the removal of scientific documents from the CDC website while allowing unvetted presentations containing unscientific assertions to proceed.

Additionally, Monarez indicated that she was instructed by Kennedy not to communicate with senators or other career scientists and that all decisions at the CDC would be

Democratic senators defended the witnesses and vaccine science. Ranking Member Bernie Sanders from Vermont called Kennedy’s actions “a dangerous war on science, public health, and the truth itself.”

“Vaccines are safe and effective,” he said. “That is not just my view, but more importantly, it is the overwhelming consensus of the medical and scientific community,” Sanders said, citing endorsements from major medical associations representing hundreds of thousands of physicians.

Monarez said that when the reconstituted ACIP meets tomorrow, “there is a real risk that recommendations could be made restricting access to vaccines for children and others in need, without rigorous scientific review. With no permanent CDC director in place, those recommendations could be adopted. The stakes are not theoretical.”

She pointed to the largest measles outbreak in more 30 years, which has killed two children. Wisconsin alone has 36 current cases measles, 22 of them children and all in unvaccinated individuals.

Cassidy indicated he would invite HHS officials including Kennedy, to testify at a future hearing to respond to the allegations. "This is how we achieve President Trump's goal of radical transparency, giving Americans the full picture so they can judge for themselves," he said.