The Centers for Disease Control and Prevention (CDC), long regarded as the nation’s bulwark against public health threats, has been thrust into turmoil following the sudden firing of its director, Susan Monarez, and the resignations of several top officials. At the heart of the upheaval is Robert F. Kennedy Jr., Secretary of the Department of Health and Human Services (HHS), whose sweeping changes and vocal criticism of the agency’s recent pandemic response have ignited fierce debate in Washington and across the public health community.
During a contentious Senate Finance Committee hearing on September 4, 2025, Kennedy faced a barrage of questions from both sides of the aisle. He defended his decision to remove Monarez less than a month after her Senate confirmation, calling the shake-up “absolutely necessary.” According to Kennedy, the CDC’s policy recommendations during the COVID-19 pandemic were “disastrous and nonsensical,” and the agency had failed in its core mission to protect Americans from chronic disease. “The people who oversaw that process are the people who will be leaving,” he declared, as reported by Chemical & Engineering News.
Kennedy’s actions have not gone unnoticed—or unchallenged. Nine former CDC directors, who served under both Democratic and Republican administrations, penned a scathing op-ed in The New York Times on September 1, 2025. They accused Kennedy of “endangering every American’s health” and described his recent moves as “unlike anything we had ever seen at the agency and unlike anything our country had ever experienced.” The directors applauded Monarez for “standing up for the agency and the health of our communities,” warning that the loss of experienced leadership would make it “far more difficult for the CDC to do what it has done for about 80 years: work around the clock to protect Americans from threats to their lives and health.”
Monarez herself, in a commentary published in The Wall Street Journal on September 4, detailed her concerns. She wrote that she was told to preapprove recommendations from the CDC’s vaccine advisory committee, which Kennedy had recently repopulated with individuals who have publicly expressed anti-vaccine rhetoric. The panel is set to meet on September 18 and 19 to discuss and possibly vote on recommendations for COVID-19, hepatitis B, measles-mumps-rubella, and respiratory syncytial virus (RSV) vaccines. Senator Bill Cassidy (R-LA) has called for the meeting’s indefinite postponement, citing “serious allegations… about the meeting agenda, membership, and lack of scientific process being followed.” Cassidy stated, “These decisions directly impact children’s health and the meeting should not occur until significant oversight has been conducted.”
The fallout from Monarez’s ouster has been swift. Three top CDC officials resigned, citing political interference in the agency’s scientific work. Demetre Daskalakis, former director of the National Center for Immunization and Respiratory Diseases, wrote in his resignation letter, “I find that the views he [Kennedy] and his staff have shared challenge my ability to continue in my current role at the agency and in the service of the health of the American people. Enough is enough.” Debra Houry, the CDC’s chief medical officer, echoed these concerns in an interview with reporters, saying, “We’ve reached the tipping point.” She also worried that upcoming immunization recommendations might be made without robust scientific backing.
Senators pressed Kennedy on the apparent contradiction between his earlier praise for Monarez—whom he described as a “public health expert with unimpeachable scientific credentials”—and his abrupt demand for her resignation. Senator Elizabeth Warren (D-MA) asked pointedly, “And in a month, she became a liar?” Kennedy responded that he had lost trust in Monarez and insisted that he did not pressure her to automatically approve the vaccine panel’s recommendations, but expected her not to reject them out of hand either.
The controversy has triggered a wave of public outcry. On August 20, more than 6,800 former and current HHS employees sent a letter to Kennedy after a gunfire attack at the CDC’s Atlanta headquarters—a shocking event in which a man, blaming the COVID-19 vaccine for his mental health struggles, fired hundreds of rounds at the building, shattering windows and killing a responding police officer. The letter urged Kennedy to “cease endangering the nation’s health by repeatedly spreading inaccurate health information,” to “affirm CDC’s scientific integrity,” and to “guarantee the safety of the HHS workforce.”
Following further chaos at the CDC, HHS employees sent another letter to Congress and Kennedy on September 3, this time calling for his resignation outright. Their demands were soon echoed by major national medical and public health associations, including the Infectious Diseases Society of America, American Association of Immunologists, and American Society for Virology. Democratic senators Elizabeth Warren, Bernie Sanders (I-VT), and Raphael Warnock (D-GA) also joined the chorus, with Warnock telling Kennedy during the hearing, “It’s clear you’re carrying out your extremist beliefs and that you represent a threat to the public health of the American people.”
Republican senators have also expressed deep concern, if not outright opposition. Senator Cassidy, who played a key role in Kennedy’s confirmation, questioned Kennedy’s decision to cancel $500 million in contracts related to mRNA vaccine development—an effort critical to Operation Warp Speed. Cassidy remarked, “It surprises me that you think so highly of Operation Warp Speed when, as an attorney, you attempted to restrict access.” He also raised alarms about Kennedy’s replacement of the CDC’s vaccine advisory committee with individuals who may have conflicts of interest, some of whom have served as paid witnesses in lawsuits against vaccines. Kennedy acknowledged that such bias could exist but argued, “If disclosed, it’s okay.”
The hearing also touched on the broader erosion of trust in public health institutions. Dr. Céline Gounder, CBS News medical contributor and editor-at-large for public health at KFF Health News, commented that the timing of the former directors’ op-ed “has everything to do with Dr. Monarez’s firing last week,” but that the underlying concerns “are really about politics and ideology taking precedence over public health and science.” She noted that the weakening of public health programs, firings across HHS, and questions about vaccine effectiveness and safety—particularly amid a serious measles outbreak in Texas—are “now diminishing trust in the very most basic of public health infrastructure in this country.”
In response to mounting calls for his resignation, Kennedy’s communications director, Andrew Nixon, told Chemical & Engineering News on September 5, “The CDC has been broken for a long time. Restoring it as the world’s most trusted guardian of public health will take sustained reform and more personnel changes.”
As the CDC’s vaccine advisory committee prepares to meet in mid-September, the future of the agency—and public trust in its work—hangs in the balance. The coming weeks will test whether Kennedy’s vision for “unbiased, politics-free, transparent, evidence-based science in the public interest” can overcome the skepticism of the scientific community and the American public, or whether the agency’s beacon, as one former director put it, is “in grave danger of being extinguished.”
