On June 11, 2025, Health Secretary Robert F. Kennedy Jr. announced a slate of eight new members to serve on the Advisory Committee on Immunization Practices, which advises the Centers for Disease Control and Prevention on national vaccine policy.

The announcement, made on the social media platform X, comes two days after Kennedy removed all 17 of the serving committee members. Kennedy called their replacements “a bold step in restoring public trust” rooted in “radical transparency and gold standard science.”

However, public health experts decried the removals, pointing to Kennedy’s promise not to change the committee and warning that the move politicizes its work and undermines its scientific integrity. Health experts have also noted that multiple new committee members appointed on June 11 have voiced anti-vaccine views that are not evidence-based.

The Conversation U.S. asked Santosh Kumar Gautam, an expert in global health policy at the University of Notre Dame, to explain how the vaccine committee’s guidance has shaped vaccine recommendations for the public, and what the changes might mean for peoples’ ability to access vaccines in the future.

What is the Advisory Committee on Immunization Practices?

The Advisory Committee on Immunization Practices, or ACIP, is a panel of experts appointed to advise the CDC on how to use vaccines to protect the health of people in the U.S. The committee’s job is to review multiple strands of scientific evidence to recommend which vaccines should be used, who should get them and when they should be given. Its guidance affects vaccine schedules for both children and adults, insurance coverage and public health policy across the country.

The committee was formed in 1964 to establish national vaccine policy as federal immunization programs began to expand. It can have up to 19 voting members, who are appointed by the secretary of Health and Human Services. Members are experts in areas such as medicine, public health and immunology. Member usually serve overlapping four-year terms to ensure continuity. All 17 previous members were appointed at different times during the Biden administration. Removing all members of the committee at once is unprecedented.

The group also includes nonvoting members from government health agencies, including the Food and Drug Administration and the National Institutes of Health. There are also representatives from more than 30 medical and public health organizations, such as the American Academy of Pediatrics and the American College of Physicians.

These nonvoting members share useful information and real-world experience such as practical issues in administering vaccines in hospitals, management of vaccine side effects and insights into adverse events. Their input helps the committee make recommendations that reflect both science and practical needs.

The committee meets three times a year to review new data on vaccine safety and effectiveness. Its next meeting is scheduled for June 25-27 and is expected to include discussions on COVID-19 and HPV vaccines, with recommendation votes planned for COVID-19 boosters, human papilloma virus and influenza vaccines. The meeting is open to the public and will be telecast live online.

What is the committee’s role in vaccine policy?

The committee makes its recommendations to the CDC by reviewing scientific evidence about a vaccine’s safety and efficacy, as well as practical issues, such as how easy a vaccine is to use, how it affects different groups, its side-effects and how it fits into the health system. The recommendations don’t just consider whether a vaccine works, but how it can be most effectively deployed to protect the American public from disease outbreaks.

The committee looks at data from clinical trials and other research to examine the most recent data on a vaccine’s safety, efficacy and use in everyday settings. When new vaccines come out or a change occurs in the way a disease spreads or behaves, the committee often revises its advice. It also responds to public health emergencies such as recent measles outbreaks in the U.S.

The committee has made many updates over time. It changed flu shot guidance when new strains appeared. It lowered the recommended age for the HPV vaccine based on new research. And it adjusted vaccine plans for meningitis to better protect people at higher risk.

What was the committee’s role during the COVID-19 pandemic?

The committee played a vital role in evaluating vaccine safety and effectiveness and authorizing the use of vaccines for different age groups by reviewing clinical trial data, from Pfizer-BioNTech, Moderna, Johnson & Johnson and other vaccine manufacturers.

The committee also developed step-by-step guidelines for who should get vaccinated first, based on how likely people were to catch the virus, their risk of serious disease, the type of work they did and whether they came from a population that was historically underserved or at higher risk. It also issued tailored guidance for pregnant and breastfeeding women, immunocompromised people and children and adolescents as more trial data became available.

These recommendations shaped vaccine rollout strategies at both national and state levels, guided insurance coverage and influenced COVID-19 vaccination policies in other countries around the world.

Who are the new members that Kennedy appointed?

Although Kennedy promised more transparency, he handpicked the advisory committee’s new members without revealing how they were selected. Historically, the body’s members are selected after an extensive vetting process that can take two years.

The newly appointed members have expertise in psychiatry, neuroscience, epidemiology, biostatistics and operations management. However, several have been linked to vaccine-related misinformation, particularly relating to COVID-19 vaccines, raising concerns about the scientific neutrality of the committee moving forward.

For example, Retsef Levi, a professor of operations management at MIT Sloan School of Management, has publicly called for suspension of COVID-19 mRNA vaccines, claiming they cause serious harm and death in young people – a statement not supported by evidence.

Another member, physician and biochemist Robert Malone, made scientifically inaccurate statements about the dangers of mRNA COVID-19 vaccines during the pandemic.

A third member, epidemiologist and biostatistician Martin Kulldorff helped write the Great Barrington Declaration, which opposed lockdowns and argued that people at low risk of severe illness or death should be allowed to contract COVID-19 to build natural immunity – a stance that was heavily debated among health experts.

What happens now?

The committee’s new makeup and Kennedy’s decades-long anti-vaccine stance threaten to erode the integrity of scientific decision-making and commitment to ethical standards in vaccine recommendations.

Kennedy’s overhaul of the Advisory Committee on Immunization Practices will likely affect how insurers, doctors and the public make decisions about vaccines – and vaccine policy generally. For example, the advisory committee’s decisions directly affect which vaccines are covered by health insurance. If a vaccine is not recommended by the committee, many insurance plans, including those under the Affordable Care Act, are not required to cover it. This means families could face out-of-pocket costs, making it harder for children to access routine immunizations.

The advisory committee also plays a key role in shaping the U.S. childhood vaccine schedule. Given Kennedy’s long-held skepticism about childhood vaccines — including those for measles and polio — some public health experts worry that the newly appointed members could push to revisit or revise vaccine recommendations, especially for newer and more debated vaccines like those for COVID-19 or HPV.

States usually base their school entry vaccine requirements on the committee’s guidelines, and insurers often use them to determine which vaccines are covered. As a result, shifts in policy to childhood vaccinations could influence both school vaccination mandates and access to vaccines for millions of children.

Santosh Kumar Gautam does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.