Fact Check: No study has ever indicated harm from thimerosal, experts assert.

Fact Check: "No study has ever indicated harm from thimerosal, experts assert."

What We Know

Thimerosal is a mercury-based preservative that has been used in multi-dose vials of vaccines and other medical products. According to the CDC, there is no evidence of harm caused by the low doses of thimerosal in vaccines, except for minor reactions like redness and swelling at the injection site. In 1999, a consensus was reached among public health agencies to reduce or eliminate thimerosal in vaccines as a precautionary measure, despite the lack of evidence indicating harm (CDC).

Research has shown that thimerosal, which contains ethylmercury, is processed by the human body more quickly than methylmercury, the latter being the type of mercury found in certain fish and known to be toxic at high exposure levels (CDC). Numerous studies have concluded that thimerosal in vaccines does not contribute to conditions such as autism, with a 2010 CDC study specifically stating that prenatal and infant exposure to thimerosal-containing vaccines does not increase the risk for autism spectrum disorder (CDC).

However, some studies, including those cited by critics of thimerosal, claim to have found harmful effects associated with its use. A paper authored by Brian Hooker and colleagues argues that over 165 studies have indicated harm from thimerosal, including links to neurodevelopmental disorders ([source-3]). They assert that the CDC's conclusions are inconsistent with their own findings of increased autism risk associated with thimerosal exposure during infancy.

Analysis

The claim that "no study has ever indicated harm from thimerosal" is partially true. While it is accurate that major health organizations, including the CDC, have found no evidence of harm from thimerosal in vaccines, the assertion overlooks the existence of studies that suggest otherwise. For instance, the paper by Hooker et al. claims that numerous independent studies have reported adverse effects linked to thimerosal, including developmental delays and autism ([source-3]).

However, the credibility of these claims is contentious. The studies cited by Hooker and his colleagues have faced criticism for methodological flaws and potential biases. In contrast, the CDC and other health organizations have conducted extensive reviews of the literature, concluding that the evidence consistently supports the safety of thimerosal in vaccines (CDC, FDA).

The debate surrounding thimerosal is further complicated by the fact that it was removed from most childhood vaccines in the U.S. in 2001, which has led to ongoing discussions about its safety and potential effects. The Institute of Medicine has also reviewed the evidence and found no causal relationship between thimerosal-containing vaccines and autism.

Conclusion

The verdict is Partially True. While major health organizations assert that there is no evidence of harm from thimerosal in vaccines, there are studies and claims from certain researchers that suggest otherwise. The existence of conflicting research highlights the complexity of the issue and the need for continued scrutiny and dialogue in the scientific community.

Sources

1. Thimerosal-Containing Vaccines and Neurodevelopmental Outcomes
2. Thimerosal and Vaccines
3. Methodological Issues and Evidence of Malfeasance in Research ...
4. Thimerosal and Vaccines
5. Thimerosal-Containing Vaccines and Neurodevelopmental ...
6. Thimerosal and Vaccines
7. C.D.C. Committee Votes Against Flu Shots With the Preservative Thimerosal