Key TakeawaysHealth Secretary Robert F. Kennedy Jr. signed off on a recommendation to remove thimerosal from all flu vaccinesThimerosal has long been targeted by anti-vaccine advocates due to safety concernsThe mercury-based preservative is considered safe by many, including the U.S. Food and Drug Administration.FRIDAY, July 25, 2025 (HealthDay News) — It's official: The controversial preservative thimerosal will be stripped from all flu vaccines distributed in the United States.U.S. Health and Human Services (HHS) Secretary Robert F. Kennedy Jr. signed off on the recommendation from an expert panel that recommended removing the mercury-based preservative from all influenza vaccines. Use of thimerosal had been largely phased out in the U.S. by 2001.Founder of an anti-vaccine group, Kennedy has often repeated debunked claims that autism may be linked to childhood vaccinations.The panel, known as the Advisory Committee on Immunization Practices (ACIP), makes vaccine use recommendations to the U.S. Centers for Disease Control and Prevention (CDC).“After more than two decades of delay, this action fulfills a long-overdue promise to protect our most vulnerable populations from unnecessary mercury exposure,” Kennedy said in a statement. “Injecting any amount of mercury into children when safe, mercury-free alternatives exist defies common sense and public health responsibility. Today, we put safety first.”Preservatives, such as thimerosal, kill or prevent the growth of bacteria and fungi, according to the U.S. Food and Drug Administration (FDA).Thimerosal has long been a target of anti-vaccine advocates due to concerns about mercury exposure, USA Today reports.In June, RFK Jr. dismissed all 17 members of ACIP and appointed eight new members, some of whom have publicly expressed skepticism about vaccines.Dr. Cody Meissner, a professor of pediatrics at Dartmouth Geisel School of Medicine, was the only ACIP member to reject the thimerosal recommendation.He told USA Today that thimerosal has been used since World War II and “no study has ever indicated any harm.” He argued that removing thimerosal from all vaccines could reduce access and increase costs.The FDA agrees.Most vaccines no longer contain thimerosal, but the FDA states that “a robust body of peer-reviewed, scientific studies conducted in the United States and countries around the world support the safety of thimerosal-containing vaccines.”More informationLearn more about flu shots at the U.S. Centers for Disease Control and Prevention.SOURCES: USA Today, July 23, 2025; U.S. Department of Health and Human Services, news release, July 23, 2025.What This Means For YouFlu shots may become pricier now that thimerosal has been removed..Sign up for our weekly HealthDay newsletter