HHS adopts advisory board's recommendation to remove mercury-based compound from flu vaccines

The Department of Health and Human Services announced Wednesday that it has adopted the Advisory Committee on Immunization Practices' recommendation to remove the mercury-based compound thimerosal from flu vaccines.

Last month, the ACIP voted to limit flu vaccines to only those free of thimerosal. The mercury-containing preservative, largely phased out of childhood vaccines by 2001, still lingers in some multi-dose flu shots. HHS Secretary Robert F. Kennedy, Jr., on Tuesday signed the advisory board's recommendations, the department said Wednesday.

“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.”

“With the U.S. now removing mercury from all vaccines, we urge global health authorities to follow this prudent example for the protection of children worldwide,” he added.

HHS also noted that vaccine manufacturers confirmed that they have the capacity to replace multi-dose vials containing mercury, ensuring adult vaccine supplies and the Vaccines for Children program will remain uninterrupted. In the U.S., 96% of flu vaccines for the 2024-2025 season are already thimerosal-free, and thus, single-dose options are not hard to come by.

The effort to remove thimerosal began in the late 1990s, sparked by growing public and scientific scrutiny of mercury exposure. In 1997, the FDA Modernization Act prompted a review of mercury in medical products, including thimerosal, which had been used since the 1930s to prevent microbial contamination in multi-dose vaccine vials.