The Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices (ACIP) is a group of medical and public health experts responsible for developing recommendations on the use of vaccines in the United States, including those for COVID-19. The committee’s members are appointed by the Secretary of Health and Human Services (HHS) and include physicians, scientists, and public health professionals with expertise in vaccinology, infectious diseases, and immunization policy. The ACIP’s recommendations are critical in guiding federal, state, and local vaccination programs, as well as informing clinical practice nationwide[1][7]. Historically, ACIP members have been selected through a process that emphasizes scientific expertise and experience in vaccine research and public health. However, in 2025, under new HHS leadership, the committee underwent significant changes. In June, HHS Secretary Robert F. Kennedy Jr. dismissed all 17 previous members and appointed eight new advisers, a departure from the traditional vetting process[4]. In September 2025, five additional members were added, bringing diverse backgrounds—including epidemiology, pharmacy, obstetrics, pediatrics, and surgery—to the committee[3]. These new appointees include Catherine Stein, PhD (epidemiology); Evelyn Griffin, MD (obstetrics/gynecology); Hillary Blackburn, PharmD, MBA (pharmacy); Kirk Milhoan, MD, PhD (pediatric cardiology); and Raymond Pollak, MD (surgery)[3]. Some of these members have publicly questioned aspects of vaccine science, reflecting a broader shift in the committee’s composition and perspectives[4]. Notable past and present ACIP members include Dr. Cody Meissner, a pediatric infectious disease expert, and Dr. Robert W. Malone, a biochemist recognized for early contributions to mRNA vaccine technology[1]. The committee’s work remains highly relevant, as it continues to advise on COVID-19 vaccine recommendations, including updates on effectiveness, safety, and implementation for the 2024–2025 season[5][6]. Recent meetings have addressed vaccine effectiveness, safety signal detection, and economic analyses of COVID-19 vaccination, with presentations from CDC scientists and external experts[6]. The ACIP’s current relevance lies in its role as the primary national body shaping U.S. immunization policy, amid ongoing debates about vaccine science and public trust. The recent changes in membership and leadership underscore the evolving nature of the committee’s influence and the importance of its recommendations for public health.