Susan Monarez told a Senate committee Wednesday that she was fired for refusing to go along with the health secretary's unscientific agenda.

Health Secretary Robert F. Kennedy Jr. said he plans to make changes to the childhood immunization schedule in September, according to ousted director of the Centers for Disease Control, Susan Monarez. Monarez detailed the conversation Wednesday at a hearing of the Senate health committee focused on the recent turmoil inside CDC.

"He said that the childhood vaccine schedule would be changing starting in September, and I needed to be on board with it," Monarez said, answering a question from committee chairman Sen. Bill Cassidy, R-La. Monarez said Kennedy offered no science or data to support a change in the schedule and that she refused to go along.

To secure his nomination in January, Kennedy assured Cassidy he would not change the childhood vaccine schedule.

Monarez also said Kennedy asked her to meet with anti-vaccine lawyer Aaron Siri.

A longtime colleague and friend of Kennedy in the anti-vaccine movement who acted as Kennedy's personal lawyer during his failed presidential campaign, Siri has made millions in lawsuits against vaccines, challenging mandates in states and representing clients who claim vaccine injuries. He once petitioned the federal government to revoke approval for a polio vaccine.

During his opening remarks, Cassidy said the hearing would focus on answering why Kennedy had fired Monarez less than a month after saying at her swearing-in that she had "unimpeachable scientific credentials."

Dr. Deb Houry, the agency's former chief medical officer, also testified about resigning in protest weeks ago, along with two other senior officials. In her opening remarks, Houry said she resigned because Kennedy had "repeatedly censored CDC science, politicized our processes, and stripped agency leaders of the ability to protect the health of the American people."

"I could not, in good conscience, remain under those conditions," she said.

A spokesperson for HHS said Monarez had been fired because she "acted maliciously to undermine the president's agenda."

The Advisory Committee on Immunization Practices (ACIP) is convening on Thursday for a two-day meeting where it plans to discuss the vaccine schedule. Kennedy fired the previous experts on that panel in June and has filled the panel with vaccine critics who lack expertise.

Ousted CDC director says Robert F. Kennedy Jr. plans to change immunization schedule