Robert F. Kennedy Jr. defended his decisions at the Department of Health and Human Services and reiterated skepticism about vaccines during a contentious Senate hearing on Sept. 4, days after a string of personnel moves at the Centers for Disease Control and Prevention sparked high-profile resignations and public criticism.
Kennedy faced questions from senators about his public statements on vaccines, including a podcast appearance in which he cast doubt on vaccine safety. "When were you lying, Sir: when you told this committee that you were not anti-vax, or when you told Americans that there’s no safe and effective vaccine?" Sen. Tina Smith, D-Minn., asked. Kennedy responded, "Both are true."
The hearing came after Kennedy, together with the Trump administration, removed Susan Monarez as director of the CDC roughly a month after her confirmation, a move that set off several high-level departures within the agency and prompted nine former CDC leaders to publicly call on Kennedy to resign. The upheaval has intensified scrutiny over leadership at HHS and the CDC’s ability to carry out its public health responsibilities.
Earlier this summer, Kennedy dismissed all 17 members of the Advisory Committee for Immunization Practices, the independent panel that develops vaccine guidance the CDC typically considers, and replaced them with new appointees. That action, along with the firings and subsequent resignations, has drawn criticism from former public health officials and congressional Democrats who say the moves undermine established vaccine policy processes.
At the Sept. 4 hearing, senators pressed Kennedy on whether his personal views on vaccines had shaped personnel decisions and policy direction at HHS. Kennedy repeatedly defended the authority of his office to restructure advisory bodies and personnel, saying the changes were made to address what he described as institutional problems within federal public health agencies.
Republican and Democratic senators debated the consequences of the leadership changes for public trust and the CDC’s capacity to respond to outbreaks. Supporters of Kennedy’s moves have argued the agency needed reform, while critics contend the dismissals and replacements threaten scientific independence and could erode public confidence in vaccine recommendations.
The Advisory Committee for Immunization Practices has long played a central role in shaping U.S. vaccine policy, issuing recommendations that inform pediatric and adult vaccination schedules and guiding responses during epidemics. The abrupt removal and replacement of its membership, and the rapid turnover in CDC leadership, have raised questions among lawmakers and former officials about how vaccine guidance will be developed and communicated moving forward.
Following the hearing, several former CDC leaders reiterated concerns about the trajectory of the agency under current HHS leadership and called for a course correction to preserve independent scientific advisory processes. The confrontation on Capitol Hill underscores growing partisan and institutional tensions over federal public health governance, particularly around vaccination policy and the roles of advisory committees.
Kennedy’s tenure so far has been marked by repeated clashes with career scientists and public health experts. The Senate hearing laid bare those tensions and highlighted a widening rift between the HHS secretary’s stated goals for agency reform and the long-standing structures that have guided U.S. vaccination policy for decades.