Health and Human Services (HHS) Secretary Robert F. Kennedy Jr. faced tough bipartisan questioning on Thursday during a Senate hearing that focused on recent leadership changes at the Centers for Disease Control and Prevention (CDC) and shifts in federal vaccine policy.
The three-hour hearing, originally intended to review President Trump’s 2026 health care agenda, turned into a heated debate over Kennedy’s decision to fire CDC Director Dr. Susan Monarez less than a month after her Senate confirmation. The termination has drawn sharp criticism and triggered the resignation of four senior CDC officials, more than 1,000 current and former HHS employees to call for Kennedy’s resignation, and a warning from former CDC directors and acting directors over his policies.
Kennedy and Dr. Susan Monarez offer very different accounts over what led to her departure. Monarez claims that she fell out of favor with Kennedy after she refused to preapprove vaccine recommendations from an advisory panel comprised largely of Kennedy appointees, some of whom have expressed anti-vaccine views. In a Wall Street Journal editorial published on Thursday, she wrote, “Public health shouldn’t be partisan. Vaccines have saved millions of lives under administrations of both parties. Parents deserve a CDC they can trust to put children above politics, evidence above ideology, and facts above fear.”
Kennedy had a different explanation. He told senators that Monarez lost his confidence during a meeting when he asked her whether she was a trustworthy person and Monarez said no. He defended her removal, stating that the CDC needs “bold, competent, creative new leadership” to regain public trust.
“We need unbiased politics and free, transparent, evidence-based science in the public interest,” Kennedy said. “Those are the guiding principles behind the changes at the CDC.”
Several senators, from both parties, challenged Kennedy’s claims and policy decisions.
Sen. Elizabeth Warren (D-Mass.) questioned whether Kennedy was truthful during his confirmation hearings when he told senators he wouldn’t restrict access to vaccines. She said his latest recommendations for COVID vaccines limit the availability of boosters at pharmacies.
“Last November, while you were under consideration to become secretary of Health and Human Services, Mr. Kennedy, you said, quote, ‘If vaccines are working for somebody, I'm not going to take them away.’” Warren said, “No exceptions, no ifs, ands, or buts. You would not take away vaccines from anyone who wanted them. Then last week you announced the COVID-19 vaccine is no longer approved for healthy people under the age of 65.”
Kennedy responded that clinical data doesn’t support widespread COVID vaccination for healthy people, citing increased natural immunity and the virus’ reduced threat level compared to five years ago.
Warren accused Kennedy of endangering public health and called for his resignation.
Republican senators also voiced alarm. Sen. John Barrasso (R-Wyo.), a physician, warned that undermining confidence in proven vaccines could reverse decades of public health progress. He questioned the safeguards Kennedy has in place to ensure decisions are based on science and not politics.
Sen. Bill Cassidy (R-La.), another physician and a key vote in Kennedy’s confirmation, expressed concern over Kennedy’s appointments to the CDC’s Advisory Committee on Immunization Practices (ACIP). Last week he urged ACIP to indefinitely postpone its upcoming meeting due to the CDC upheaval. During the hearing, he noted that some appointees had served as paid expert witnesses in lawsuits against vaccine manufacturers, raising questions about potential conflicts of interest.
“If we put people who are paid witnesses for people suing over vaccines, that actually seems like a conflict of interest,” Cassidy said.
Kennedy disagreed, acknowledging the appearance of bias but stating that their disclosures negate any conflict.