U.S. Health and Human Services (HHS) Secretary Robert F. Kennedy Jr. and Secretary of Education Linda McMahon attend a Make America Healthy Again (MAHA) Commission event, in the East Room of the White House in Washington, D.C., U.S., May 22, 2025.
Evelyn Hockstein | Reuters
A key, revamped government panel of vaccine advisors appointed by Health and Human Services Secretary Robert F. Kennedy Jr. will soon vote on a shot preservative that contains mercury, which is safely used in some flu jabs but has been incorrectly linked to autism in the past.
The Advisory Committee on Immunization Practices, or ACIP, will hear a presentation about the preservative, called thimerosal, at a planned meeting on June 26. The panel will also vote on “thimerosal-containing vaccine” recommendations, according to a draft agenda for the two-day meeting posted on Wednesday.
It is the panel’s first meeting with Kennedy’s newly appointed members, many of whom are well-known vaccine critics. He named the eight advisors last week after firing the previous 17 members of the committee, which advises the Centers for Disease Control and Prevention on vaccine policy.
It is unclear what will be discussed in the presentation or what exactly the panel will vote on.
Thimerosal has been widely used for decades as a preservative to prevent the growth of harmful bacteria in several medicines and vaccines with multiple doses. But its use in approved vaccines has dropped sharply as manufacturers have shifted to single-dose packaging for their shots, which don’t require preservatives.
Some multi-dose forms of flu vaccines for adults still contain thimerosal, including Sanofi‘s Fluzone and two shots from biotech company CSL Seqirus. All vaccines routinely recommended for children 6 years of age and younger in the U.S. are available in formulations that do not contain thimerosal, according to the Food and Drug Administration.
The FDA and other health bodies have emphasized that many well-conducted scientific studies have found no link between thimerosal and autism, despite unfounded concerns decades ago about a potential connection.
“The scientific evidence collected over the past 20+ years does not show any evidence of harm, including serious neurodevelopmental disorders, from use of thimerosal in vaccines,” the FDA said on its website.
The new ACIP members will play a significant role in shaping immunization policy in the U.S., as the panel reviews vaccine data and makes recommendations that determine who is eligible for shots and whether insurers should cover them, among other efforts. The committee is also slated to review data and vote on other vaccines, including shots for Covid and RSV during the two-day meeting.
