Fact Check: Thimerosal has been used in vaccines since before World War II!

Fact Check: "Thimerosal has been used in vaccines since before World War II!"

What We Know

Thimerosal, a mercury-based preservative, has been used in vaccines for several decades. According to the CDC, it has been utilized in multi-dose vials of vaccines to prevent bacterial and fungal contamination. The use of thimerosal in vaccines predates World War II, with its introduction in the 1930s. The Wikipedia entry on thimerosal confirms that it has been used in various medical products, including vaccines, since its development in the early 20th century.

However, thimerosal was removed from most childhood vaccines in the United States in 2001 as a precautionary measure, despite studies showing no evidence of harm from the low doses used in vaccines (CDC) [source-1]. Notably, the measles, mumps, and rubella (MMR) vaccine has never contained thimerosal [source-1].

Analysis

The claim that thimerosal has been used in vaccines since before World War II is partially true. While it is accurate that thimerosal was introduced in the 1930s and used in vaccines prior to World War II, the context of its use is essential. The CDC states that thimerosal was primarily used in multi-dose vials to prevent contamination, which is a critical aspect of its application in vaccines [source-1].

The reliability of the sources is high; the CDC is a reputable public health organization, and the information provided is supported by extensive research. The Wikipedia entry also corroborates the historical use of thimerosal, although it is less authoritative than the CDC [source-3].

However, the narrative surrounding thimerosal has been clouded by concerns regarding its safety, particularly in relation to autism. The World Health Organization and various studies have consistently found no link between thimerosal and autism or other neurodevelopmental disorders, reinforcing the safety of its use in vaccines at the levels present [source-1][source-7].

It is also important to note that thimerosal has been largely phased out of vaccines in the United States and many other countries, with only a few vaccines still containing it, primarily in multi-dose vials [source-6][source-8]. This shift reflects a precautionary approach rather than evidence of harm.

Conclusion

The claim that "Thimerosal has been used in vaccines since before World War II" is partially true. While it accurately reflects the historical timeline of thimerosal's use in vaccines, it lacks context regarding its safety and the subsequent removal from most childhood vaccines. The evidence supports that thimerosal was used safely for decades, but the ongoing concerns and eventual removal from most vaccines highlight the complexities surrounding public health decisions.