WASHINGTON (TNND) — Sen. Bill Cassidy, a Republican from Louisiana and the chair of the Senate Health, Education, Labor and Pensions Committee, said the termination of Centers for Disease Control and Prevention director Susan Monarez, along with the resignations of other high-profile CDC officials, "will require oversight by the HELP Committee."

The recent departures signal a major shake-up in CDC leadership amid Health Secretary Robert F. Kennedy Jr.'s efforts to usher in new procedures and policies for vaccine administration and research.

During Kennedy's confirmation hearing, he promised Cassidy that he would not undermine the integrity of the CDC's immunization practices. Cassidy was a deciding vote for Kennedy's nomination.

“If confirmed, (Kennedy) will maintain the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices — without changes,” Cassidy declared with confidence.

On Wednesday, the White House fired Monarez, who was just a month into her role as the head of the CDC.

The White House's termination notice to Monarez came hours after the Department of Health and Human Services announced that Monarez was no longer director of the CDC.

Monarez's lawyers disputed HHS's announcement, writing that she "has neither resigned nor received notification from the White House that she has been fired, and as a person of integrity and devoted to science, she will not resign.”

Her lawyers accused Kennedy, who has long been critical of vaccines, of targeting Monarez for refusing to fall in line with his vaccine policies that are "putting millions of American lives at risk."

“When CDC Director Susan Monarez refused to rubber-stamp unscientific, reckless directives and fire dedicated health experts, she chose protecting the public over serving a political agenda,” the lawyers, Mark S. Zaid and Abbe Lowell, wrote in a statement. “For that reason, she has been targeted.”

Following Monarez's termination, four other senior officials at the CDC resigned: Dr. Debra Houry, the CDC’s chief medical officer; Dr. Demetre Daskalakis, director of the National Center for Immunization and Respiratory Diseases; Dr. Daniel Jernigan, the director of the National Center for Emerging and Zoonotic Infectious Diseases; and Dr. Jennifer Layden, director of the Office of Public Health Data, Surveillance, and Technology.

The National News Desk reached out Cassidy's office for comment.