Many parents are against vaccinating their children due to a possible link between thimerosal containing vaccines and some neuropsychological disorders. These parents should be aware of the importance of vaccinations in general, the specific use of thimerosal as a preservative, the different tests that have been done and measures put in place for the safety of the recipients.
The human is a complex animal. We have an entire organ system dedicated to fighting diseases for us. That system is called the immune system. In order to know the importance of vaccines we need to understand what they do and how they work within the immune system. Antigens are foreign to the body including bacteria and viruses that can cause diseases. Antibodies are what the body’s immune system produces to recognize the antignes. The human immune system has two types of immunity; passive and active. Passive immunity is the transfer of antibodies from one individual to another. For example, mother and infant. Mother will pass along some of her antibodies to her infant during pregnancy. These antibodies will provide immunity to those specific antigens for only a short amount of time; typically a year. Active immunity is the process in which our body is exposed to a certain antigen and it produces antibodies on its own. Active immunity can be gained by recovering from a certain disease itself or by having vaccination administered (Centers for Disease Control and Prevention). Over time vaccinations have decreased the chance of humans contracting a deadly disease and have prolonged life. According to a textbook published by the Center for Disease Control and Prevention (CDC), Epidemiology and Prevention of Vaccine-Preventable Diseases, “Vaccines interact with the immune system and often produce an immune response similar to that produced by the natural infection, but they do not subject the recipient to the disease and its potential complications.” (CDC 3).
The Food and Drug Administration (FDA) defines preservatives as “compounds that kill or prevent the growth of microorganisms, particularly bacteria and fungi”. The preservatives are used to prevent growth of bacteria and/or fungi in the event there is contamination of a certain vaccination vial. In 1968 the United States Codes of Federal Regulations required the addition of preservative to multi-use vaccination bottle. The decision came with much research on preservatives and the previous deaths due to contaminated vaccines. In 1928, Dr. George Thomas administered 42 vaccinations mid-month of January that year. By the end of the month 12 of those children who received the vaccination fell ill and died. After investigation it was determined that vaccination had been contaminated with live staphylococci. Along with the decision by the United States Federal Code of Federal Regulations to add preservatives in the vaccines, they also stated that “the preservative used shall be sufficiently non-toxic so that the amount present in the recommended dose of the product will not be toxic to the recipient…”. Thimerosal is one of the most widely used preservatives and it’s the preservative in question related to neuropsychological disorders. Thimerosal is about 50% mercury by weight and is metabolized into ethyl mercury and thiosalicylate. Thimerosal met the requirements to be used as a preservative; it kills potentially negative organisms/pathogens and is able to prevent growth of fungi. There have also been many test done, dating back to the 1930’s, to determine the safety of this preservative (FDA).
The argument against this is that the thimerosal preservative is part mercury. Mercury is toxic and if exposed to high levels could cause neuropsychological disorders such as Autism or Autism spectrum disorders. Per Prates findings, Autism related cases have increased at an annual rate of 10-17% since the 1980’s. Since then there have been a higher number of vaccinations administered during the first 15 months of