HHS Finalizes Removal of Thimerosal from All U.S. Influenza Vaccines
SHERIDAN, WYOMING – July 25, 2025 – In a significant move reshaping national vaccine policy, the U.S. Department of Health and Human Services (HHS) has announced it will eliminate thimerosal from all influenza vaccines distributed in the United States. The decision follows a unanimous vote by the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) on June 26, 2025, and marks the end of an era for a preservative that has been both a practical necessity and a source of public debate for over two decades.
Strategic impact on manufacturers and supply chain
While thimerosal is currently used in only about 4% of flu vaccines—mainly multi-dose vials—the HHS ruling will require vaccine manufacturers to fully transition to thimerosal-free production. This includes replacing the final few thimerosal-containing products, namely two from Seqirus and one from Sanofi Pasteur, according to CDC data.