U.S. Demands Thimerosal Removal from Gavi Vaccines, Threatens Funding
The U.S. government has issued an ultimatum to Gavi, the Vaccine Alliance, an international organization providing vaccines to children in low-income countries. The Department of Health and Human Services (HHS) informed Gavi that it must remove the preservative thimerosal from its vaccines or face the withholding of future U.S. funding. This development was first reported by Reuters.
Basis of the U.S. Demand
The U.S. demand stems from an unsubstantiated theory suggesting a link between the mercury in thimerosal and autism. Thimerosal is a chemical compound used as a preservative in vaccines.
The U.S. demand stems from an unsubstantiated theory suggesting a link between the mercury in thimerosal and autism.
Strained U.S.-Gavi Relations
This ultimatum represents the latest point of contention between Gavi and the United States, historically a significant funder. In June, the U.S. cut over a billion dollars in previously pledged funds to Gavi. At that time, HHS Secretary Robert F. Kennedy Jr. stated that Gavi "ignores the science" regarding vaccine safety. The State Department confirmed that Secretary Kennedy is directing the U.S. government's relationship with Gavi on this matter.
Understanding Thimerosal: Safety and Function
Thimerosal has been used safely in medications and vaccines since the 1930s. Its primary function is an antimicrobial property, preventing the growth of bacteria and fungi in multi-dose vaccine vials. This is particularly crucial in low-income countries where multi-dose vials are common due to their cost-effectiveness and reduced storage requirements compared to single-dose vials, which are predominantly used in the U.S. and Europe.
Approximately 14% of Gavi's vaccine portfolio, including the pentavalent, DTP, and hepatitis B vaccines, contains thimerosal in multi-dose formulations.
Thimerosal contains ethylmercury, which rapidly exits the body and is not considered harmful in the quantities found in vaccines. This differs from methylmercury, a more dangerous type that can accumulate in the body.
Major health institutions, including the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and the Food and Drug Administration (FDA), have affirmed thimerosal's safety, stating there is no evidence of toxicity from vaccine exposure or a link between thimerosal and autism.
Despite this scientific consensus, HHS Secretary Kennedy maintains that thimerosal's mercury is a "very potent neurotoxin." In 2001, the U.S. removed thimerosal from most routine childhood vaccines as a precautionary measure to address public trust concerns, not due to scientific evidence of harm. Autism rates continued to increase after this removal.
The Current Standoff
The U.S. has requested a "detailed action plan with a timeline for the phase-out of thimerosal-containing vaccines" from Gavi. The stated aim is to align vaccine standards in low-income countries with those in the U.S., Canada, and most European nations. Gavi has indicated that it is in communication with the U.S. on this subject and that any changes would require a decision by its Board, guided by scientific consensus. HHS reported that Gavi has not agreed to develop such a plan.
Experts, such as virologist Angela Rasmussen, describe the U.S. demand as "extortion," noting its divergence from scientific evidence.
There are concerns among vaccine experts about the potential consequences if Gavi were to comply with the request to eliminate thimerosal, given its importance for vaccine contamination prevention in multi-dose vials used in low-income settings.