Fact Check: 96% of flu shots in 2024-2025 won't contain thimerosal.

Fact Check: "96% of flu shots in 2024-2025 won't contain thimerosal."

What We Know

The claim that "96% of flu shots in 2024-2025 won't contain thimerosal" is based on recent data from the CDC. For the 2024-2025 flu season, it has been reported that approximately 96% of all influenza vaccines in the United States are expected to be thimerosal-free. This is largely due to the fact that only multi-dose vial formulations of influenza vaccines will contain thimerosal, while most of the projected supply will be thimerosal-free or thimerosal-reduced (i.e., preservative-free) (CDC, USA Today).

Thimerosal is a mercury-containing preservative that has been used in some vaccines, particularly in multi-dose vials, to prevent bacterial contamination. However, it has been largely phased out of childhood vaccines and is now primarily found in certain formulations of the influenza vaccine (Children's Hospital of Philadelphia).

Analysis

The assertion that 96% of flu shots will not contain thimerosal is supported by multiple credible sources. The CDC has explicitly stated that most flu vaccines for the 2024-2025 season will be thimerosal-free, with only specific multi-dose vial formulations containing the preservative (CDC). This aligns with data reported by the New York Times and USA Today, which both reference CDC statistics indicating that 96% of flu vaccines were thimerosal-free during the last influenza season (New York Times, USA Today).

However, it is important to note that while the percentage is accurate, the context matters. The remaining 4% of flu vaccines that do contain thimerosal are primarily in multi-dose vials, which are less commonly used in many healthcare settings. This distinction is crucial as it highlights that the majority of vaccines administered will indeed be thimerosal-free, but a small fraction will still contain the preservative.

The sources cited are reliable, with the CDC being a primary health authority and the New York Times and USA Today being well-established news organizations. However, the framing of the claim could lead to misunderstandings about the prevalence of thimerosal in flu vaccines, as it may imply that thimerosal is a widespread issue when it is not.

Conclusion

Verdict: Partially True
The claim that "96% of flu shots in 2024-2025 won't contain thimerosal" is partially true. While it is accurate that 96% of flu vaccines will be thimerosal-free, it is essential to recognize that a small percentage (4%) will still contain thimerosal, specifically in multi-dose vial formulations. Thus, the claim is true in terms of the percentage but may be misleading without the context of how thimerosal is used in vaccines.

Fact Check: 96% of flu shots in 2024-2025 won't contain thimerosal.