Thiomersal and vaccines

Thiomersal and Vaccines

Thiomersal (also known as Thimerosal in the United States) is an organomercury compound used as an antiseptic and antifungal agent. It has a particular role in the preservation of vaccines, which is the focus of this article.

History

Thiomersal was developed in the 1920s by Eli Lilly and Company. It was introduced to prevent bacterial and fungal contamination in vaccines and other pharmaceutical products. The use of Thiomersal in vaccines became widespread due to its ability to prevent the growth of bacteria and fungi in multi-dose vials of vaccines.

Use in Vaccines

Thiomersal is used as a preservative in some vaccines due to its efficacy in preventing bacterial and fungal contamination, particularly in multi-dose vials. It is used in trace amounts and is metabolized into ethylmercury and thiosalicylate in the body.

Safety and Controversy

The safety of Thiomersal in vaccines has been a topic of controversy. Concerns have been raised about the potential effects of its mercury content on human health, particularly in relation to autism and neurodevelopmental disorders. However, numerous scientific studies and major health organizations, including the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), have found no evidence of harm caused by the low levels of Thiomersal in vaccines.

Current Use

In the United States, Thiomersal is no longer used in most childhood vaccines, with the exception of some influenza vaccines. However, it is still used in some vaccines in other countries, particularly in multi-dose vials, due to its effectiveness as a preservative and its low cost.

See Also

• Vaccine
• Mercury
• Eli Lilly and Company
• World Health Organization
• Centers for Disease Control and Prevention