The US Department of Health and Human Services (HHS) has announced that it will officially eliminate the use of thimerosal, a mercury-based preservative, from all influenza vaccines distributed in the country.
The move comes despite decades of scientific evidence showing no harm associated with the ingredient, which has been used in multi-dose vaccines to prevent bacterial contamination.
The decision follows a recommendation made in June by the Advisory Committee on Immunization Practices (ACIP), a key government vaccine panel. The panel was recently restructured by HHS Secretary Robert F. Kennedy Jr., who replaced several members with individuals known for their anti-vaccine views. Kennedy, who has long opposed the use of thimerosal, called the removal a “long-overdue promise” to protect vulnerable populations, urging global health authorities to adopt similar measures.
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While thimerosal is already absent from the vast majority of flu vaccines, accounting for only 4% to 5% of the US supply, the move will affect certain multi-dose vials, including some formulations of Sanofi’s Fluzone and two products from CSL Seqirus. Vaccine manufacturers have assured the HHS that they can meet demand with thimerosal-free alternatives, and federal programs that provide free shots to uninsured and underinsured children will not be disrupted.
However, some public health experts warn that eliminating these vaccine options could unintentionally reduce access and vaccination rates. They also caution that the move may lend undue credibility to debunked claims linking thimerosal to developmental disorders, such as autism, a connection discredited by over 40 scientific studies spanning decades.
