Robert F. Kennedy Jr., the Trump-appointed secretary of Health and Human Services (HHS), has made it clear that radical change within the health department is his goal. Amidst the avalanche of changes that he has made to the Centers for Disease Control and Prevention (CDC), Food and Drug Administration, National Institutes of Health, and other agencies under his department’s supervision, it can be difficult to keep track of the most problematic decisions.
One change that has drawn particular attention from healthcare professionals is the dissolution and reinstatement of the Advisory Committee on Immunization Practices (ACIP) by Kennedy. In June 2025, Kennedy dismissed all seventeen members of the committee and began replacing them with his own appointees.
The ACIP creates the official federal recommendations for vaccines, including their timing, dosage, and contraindications. These guidelines are what doctors look to for guidance when deciding how to provide patients with the best care. When you go in for a routine check-up, it is in part ACIP’s recommendations that determine whether you are advised to receive a vaccine.
Changes to vaccine recommendations come naturally as vaccine technology changes. There are always new vaccines being developed, old vaccines being updated, and new data to consider, which is why it is so crucial for ACIP members to be well-informed, critically thinking experts in their fields—and, for so long, they have been. “For over fifty years, the ACIP has been the gold-standard source for evidence-based vaccine recommendations in the United States,” said Jason Schwartz, an associate professor at the Yale School of Public Health.
Yet Kennedy’s overhaul of the committee prioritizes members’ skepticism of vaccines over expertise. Of the new members, only one has previously served on the committee. The new twelve-member panel comprises multiple individuals with ties to explicitly anti-vaccine organizations, and its members by and large lack the technical knowledge and experience of their predecessors.
Since its dissolution and reinstatement, ACIP has held two meetings. The first, in June 2025, with just seven initial members, demonstrated a conspicuous difference in approach compared to previous committee meetings. “It was moving at a much less formal, much quicker speed,” Schwartz said. Previously, issues were discussed over the course of several meetings before being voted on, with extensive additional research and deliberation occurring between meetings among subgroups working closely with CDC scientists. In the June meeting, one speaker presented discredited claims about thimerosal, a mercury-based vaccine preservative used in a minority of flu vaccines, as well as many common cosmetics items, citing a study that does not exist. The committee then voted to recommend all Americans receive only thimerosal-free vaccines, despite the absence of new evidence or safety signals. Thimerosal has long been found to be safe; no rigorous study has linked the low doses of thimerosal typical to pharmaceutical uses to harm beyond minor reactions like swelling at the injection site.
Five more members were added in September 2025, days before a key meeting to decide on multiple recommendations for the fall season. During the September meeting, the committee voted on several new vaccine recommendations.
The committee voted to no longer recommend the combined measles, mumps, rubella, and varicella (MMRV) vaccine before four years of age, citing concerns over the risk of febrile seizures. Previously, children could receive the MMRV vaccine starting at one year old. Perhaps betraying confusion, the committee members initially voted against aligning the new recommendation with the CDC’s Vaccines for Children (VFC) program but then re-voted in favor of alignment. Ultimately, the changes mean that nearly half of American children who are underinsured and covered by VFC will no longer be eligible to receive the MMRV vaccine for free until they are four years old.
The board also voted to no longer recommend the COVID-19 vaccine for adults, instead stating that vaccinations should be based on individual decision-making. Most strikingly, the committee initially tied in a six-to-six vote over a recommendation to require prescriptions for COVID-19 vaccines, which would drastically reduce patient access, especially among those without primary care providers or lacking insurance. The recommendation did not pass after the ACIP chair voted no to break the tie.
The new members of the ACIP have shown a stark departure from the evidence-based decision-making that has characterized the committee since its inception. Doctors are left without the reliable framework they have depended on for decades. New recommendations threaten to leave millions without insurance coverage for vaccines. The government loses another credible voice from ACIP—the foundation of health policy in the United States continues to crumble.