Fact Check: "96% of US influenza vaccines were thimerosal-free in 2024-25."
What We Know
For the 2024-2025 influenza season, manufacturers are projected to supply approximately 148 million doses of flu vaccine in the United States. According to the CDC, most of these vaccines will be thimerosal-free or thimerosal-reduced (i.e., preservative-free). However, it is important to note that only multi-dose vial formulations of influenza vaccines will contain thimerosal. This means that while a significant portion of the vaccine supply will not contain thimerosal, some vaccines will still include it, particularly those in multi-dose vials.
Analysis
The claim that "96% of US influenza vaccines were thimerosal-free in 2024-25" is partially supported by the information available. The CDC states that the majority of the projected flu vaccine supply for the season will be thimerosal-free, but does not provide a specific percentage. The assertion of 96% appears to be an extrapolation rather than a direct statement from credible sources.
The American Academy of Pediatrics and other health organizations have advocated for the removal of thimerosal from vaccines, which has led to a significant reduction in its use. However, the exact percentage of thimerosal-free vaccines can vary based on the type of vaccine and the manufacturing practices of different companies.
Furthermore, a review of studies indicates that while thimerosal was historically used as a preservative in vaccines, its association with autism has been widely discredited in the medical community (Hurley et al.). This context is important as it highlights the ongoing efforts to reduce thimerosal in vaccines, but it does not confirm the specific percentage mentioned in the claim.
Conclusion
The claim that "96% of US influenza vaccines were thimerosal-free in 2024-25" is Partially True. While it is accurate that a majority of the influenza vaccines will be thimerosal-free, the specific figure of 96% lacks direct support from authoritative sources. The CDC confirms that most vaccines will not contain thimerosal, but does not specify a precise percentage, leaving room for interpretation.