Fact Check: "Thimerosal is in 5% of multidose flu vaccine vials, impacting vaccine cost and availability."
What We Know
Thimerosal is an ethyl mercury-based preservative that has been used in multi-dose vials of vaccines to prevent contamination from bacteria and fungi (CDC, CDC). Multi-dose vials are designed to be accessed multiple times, which increases the risk of contamination. The Centers for Disease Control and Prevention (CDC) states that thimerosal is still present in some multi-dose flu vaccine vials, while most single-dose vials and pre-filled syringes do not contain preservatives (CDC).
The CDC has indicated that as of recent estimates, about 4% of the U.S. flu vaccine supply is available in multi-dose vials containing thimerosal (CIDRAP). This suggests that thimerosal is not present in the majority of flu vaccines, particularly those administered as single doses.
Analysis
The claim that "Thimerosal is in 5% of multidose flu vaccine vials" is supported by the CDC's estimate that approximately 4% of the flu vaccine supply is available as multi-dose vials containing thimerosal (CIDRAP). This aligns closely with the claim, making it factually accurate.
However, the assertion that thimerosal impacts vaccine cost and availability is more complex. While thimerosal is used as a preservative in multi-dose vials, the actual impact on cost and availability is not explicitly detailed in the sources. The CDC and other health authorities have stated that thimerosal is safe at the levels used in vaccines and that its removal from childhood vaccines was a precautionary measure rather than a response to safety concerns (CDC, CDC).
The presence of thimerosal in only a small percentage of flu vaccines suggests that its impact on overall vaccine availability is minimal. Furthermore, the majority of flu vaccines are available in thimerosal-free formulations, which could mitigate any potential issues related to cost and availability stemming from thimerosal use.
Conclusion
The claim that "Thimerosal is in 5% of multidose flu vaccine vials" is Partially True. While the percentage is accurate, the assertion that it significantly impacts vaccine cost and availability lacks sufficient evidence. The presence of thimerosal in a small fraction of flu vaccines does not appear to have a substantial effect on the overall availability of vaccines, especially given the availability of thimerosal-free options.
