As required by law, the federal government has renewed the charter for the CDC’s Advisory Committee on Immunization Practices (ACIP), but questions remain about whether new members will be appointed and if the panel’s duties might change going forward.

The ACIP’s 2-year charter was due for renewal on April 1. In a notice published in the Federal Register, the US Department of Health and Human Services (HHS) said it was renewing the charter through 2028 and laid out criteria for selection of ACIP members and the panel’s duties.

The posted charter contained less detail than the current charter. The notice and the current charter said the panel would be made up of up to 19 voting members. The notice said ACIP’s focus would be on reviewing vaccine data, conducting an “evidence-based process” for developing vaccine recommendations, and ensuring publication of the child and adolescent and adult immunization schedules.

The panel is currently in a state of flux as a result of a March 16 ruling by a federal judge in a lawsuit led by the American Academy of Pediatrics and joined by the American College of Physicians, American Public Health Association, Infectious Diseases Society of America, Massachusetts Public Health Alliance, and Society for Maternal-Fetal Medicine. The judge found that a majority of the current ACIP members were not qualified to serve and temporarily put those members’ appointments on hold and halted all the changes implemented by the committee.

The HHS has not said if it will appeal. When asked whether the agency will appoint new ACIP members, HHS spokesman Andrew Nixon said, “The ACIP charter renewal and its publication are routine statutory requirements and do not signal any broader policy shift.”

Added Nixon, “Unless officially announced by HHS, any assertions about next steps are speculation.”

The current charter calls for ACIP members to be knowledgeable in immunization practices and public health or have expertise in the use of vaccines and other immunobiological agents in clinical practice or preventive medicine, expertise with clinical or laboratory vaccine research, or in assessment of vaccine efficacy and safety. It also requires a member or members knowledgeable about consumer perspectives and/or social and community aspects of immunization programs.

The renewal notice said membership should be geographically balanced and include individuals from a “balance of specialty areas (eg, biostatistics, toxicology, immunology, epidemiology, pediatrics, internal medicine, family medicine, nursing, consumer issues, state and local health department perspective, academic perspective, public health perspective, etc.).”

In late March, attorney Aaron Siri, representing an anti-vaccine organization, petitioned HHS to change ACIP’s membership. His group is seeking to add voting members who have expertise in “identification, assessment, or treatment of vaccine injuries” and that “at least two members shall have direct and substantial experience advocating for and/or treating those injured by vaccines.” Those members also should not have worked for the Clinical Immunization Safety Assessment Project or “as part of any other government or industry funded program, research, or project,” according to the petition.

In place of the current ACIP liaison groups — which have been barred from formal participation by the HHS — the petition seeks to add nonvoting members not only from medicine, nursing, academic and research institutions, public health organizations, and industry but also from organizations that represent “populations disproportionately affected by vaccine-preventable diseases,” “individuals who have experienced adverse events following immunization,” and “organizations that advocate for informed consent.”

Alicia Ault is a St. Petersburg, Florida-based freelance journalist whose work has appeared in many health and science publications, including Smithsonian.com. You can find her on X @aliciaault and on Bluesky @aliciaault.bsky.social.