Former Centers for Disease Control and Prevention Director Susan Monarez testifies Wednesday before the Senate Committee on Health, Education, Labor, and Pensions hearing to examine reviewing recent events at the Centers for Disease Control and Prevention and implications for children's health on Capitol Hill, in Washington. (AP Photo/Jose Luis Magana)

WASHINGTON (AP) — The U.S. public health system is headed to a “very dangerous place” with Health Secretary Robert F. Kennedy Jr. and his team of anti-vaccine advisers in charge, fired Centers for Disease Control and Prevention chief Susan Monarez warned senators on Wednesday.

Describing extraordinary turmoil inside the nation’s health agencies, Monarez and former CDC Chief Medical Officer Chief Debra Houry said Kennedy, a longtime vaccine skeptic, and his political advisers repeatedly rebuffed data supporting the safety and efficacy of vaccines.

Monarez’s revelations to senators raised serious questions, even among some Republicans, about Kennedy’s self-professed commitment to employ “gold-standard science” for developing public health guidance, including around the nation’s vaccination schedule. Her testimony was given to the Senate’s health committee just a day before a vaccine panel is set to consider major changes to the routine vaccinations recommended for the nation’s children.

Monarez, who was fired after 29 days into her tenure over vaccine policy disagreements with Kennedy, told senators that deadly infectious diseases like polio could be poised to make a devastating comeback if the health secretary and his team continue their public campaign against routine shots.

“I believe preventable diseases will return, and I believe we will have our children harmed by things they don’t need to be harmed by,” Monarez said before the Senate health committee.

Despite her concerns, some Republicans continued to cast doubts on Wednesday about Monarez’s account of her exchanges with Kennedy, firmly throwing their support behind the health secretary. A spokesperson for Kennedy did not provide a response to Monarez’s testimony. In a post on X thanking a Republican senator for support during the hearing, Kennedy said “we will earn back Americans’ trust and refocus the CDC on its core mission.”

Data and scientists removed from the conversation about vaccines, Monarez said

Monarez said Kennedy told her she would need to quit the job if she refused to sign off on the new vaccine recommendations that are expected to be released later this week by the CDC’s advisory vaccine panel, which Kennedy has stocked with some medical professionals who are vaccine skeptics. She said that when she asked for data or science to back up Kennedy’s request to change the childhood vaccination schedule, he offered none.

She added that Kennedy told her “he spoke to the president every day about changing the childhood vaccination schedule.”