Thimerosal is an ethyl mercury that has been removed from antibiotics since 2001, because people were worried about mercury poisoning. It was originally used to preserve multi-dose vaccines. Most of the time now vaccines come pre-loaded in a syringe so the thimerosal is not needed. Before 2001 thimersosal was used in the multi-dose flu vaccine, the doctor would use a new syringe every time but the movement in and out of the vaccine bottle could lead to contamination, the thimerosal was added in a low dose to prevent bacteria growth within the bottle (3).
Thimerosal contains ethyl mercury, what people know as poisonous is methyl mercury. Ethyl mercury and methyl mercury have a difference of one carbon, this changes how it is processed by the body. Since ethyl mercury is a bigger molecule it is processed by the body and secreted faster. While methyl mercury is a smaller molecule which can be further absorbed into the body so it stays in the body much longer (3).
(1)The other concern about thimersoal is about it potentially causing autism in some young children. Many studies have shown that it is impossible for thimerosal to cause autism. When someone experiences mercury poisoning they have completely different symptoms than autism. There is no scientific evidence that states thimerosal can cause autism (3).
140 Reasons – Part 3. (2018, November 29). Retrieved May 2, 2020, from
https://autismum.com/series/jagganath-chatterjee/40-reasons-part-3/
2Children's Hospital. (2014, November 7). Thimerosal. Retrieved May 2,
2020, from
https://www.chop.edu/centers-programs/vaccine-education-center/vaccine-ingredients/thimerosal
3Vaccines: Vac-Gen/Additives in Vaccines Fact Sheet. (2019, August 5).
Retrieved May 2, 2020, from
https://www.cdc.gov/vaccines/vac-gen/additives.htm
