Perservatives

Preservatives are used prevent contamination in multi-dose vaccines, thimerosal was a widely used preservative in flu vaccines (2).  

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 

Inactivating ingredients

 An inactivating ingredient is a chemical that is used to till the virus or weaken toxins during the manufacturing stage, the virus or toxin is then clean though it is possible that trace amounts of the inactivating agent ends up in the vaccine (3). 

Formaldehyde is used as an inactivating ingredient, and while in large concentrations it can cause DNA damage the amount used in vaccines is minimal as well as diluted. In all of the vaccines combined a child would only maybe receive as much as 0.7 -0.8 mg of formaldehyde. The body experiences much more formaldehyde than that on a daily basis. It is used in the synthesis of DNA, so naturally 2.5ug of formaldehyde can be found in 1ml of blood at any time. So if the child is five kg, that means they would have on average 85ml of blood per Kg. Making the total amount of formaldehyde found in the child's blood to be 1.1mg which is much larger than the amount in all of the vaccines on the CDC schedule combined (2). 

(1)

¹Amazon.com: Online Shopping for Electronics, Apparel ... (n.d.). Retrieved May 2, 2020, from https://www.amazon.com/

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