In 1998, Andrew Wakefield published a paper, claiming that the measles, mumps, and rubella (MMR) vaccine caused symptoms including intestinal inflammation, among other things that led to the consequent development of autism. This paper was scientifically flawed and even fraudulent due to data misrepresentation. Wakefield claimed that autism arose as a result of intestinal inflammation when really intestinal symptoms were observed after symptoms of autism developed. Over the next couple of years after this paper was published in Lancet, this possible connection between MMR and autism was studied extensively as debates raged on the possible link between vaccinations and autism.

The greatest reason that parents refuse to vaccinate their children is due to concerns on vaccine safety. Information gathered from the media or their peers tends to raise doubt over the possibility of long-lasting adverse effects. In 2013, the CDC published a study contributing to the research showing that vaccines do not have any role in the development of ASD. They focused on the quantity of antigens, substances in vaccines that produce antibodies in the body, given during the first two years of life. The CDC researchers found that the total number of antigens from vaccines was the same between children with ASD and without.

Other studies have probed further into the actual chemicals and ingredients found in vaccines. One of the vaccine ingredients in specific is thimerosal, a mercury-based preservative used to prevent germs from contaminating vials of vaccines. In the 1990s, lawmakers and public health workers became increasingly concerned with mercury exposure in that it was known to have harmful effects. A 2004 review by the IOM established that “the evidence favors rejection of a causal relationship between thimerosal-containing vaccines and autism.” Although thimerosal was removed from most vaccines, autism diagnosis rates did not drop but rather continued to rise. Taylor et al. conducted an analysis of five cohort and five case-control studies. The researchers of this study concluded that cohort and case-control data both found no evidence for increased risk of autism development following MMR, Hg (mercury), or thimerosal exposure when studied.

No relationships have been found between vaccines and ASD. Even though there has been extensive evidence that vaccines are reliable and efficient, parents have decided not to get their children vaccinated which can be dangerous due to the continuing presence of diseases like polio or measles. Kids get reactions to vaccines all the time, from mild fevers to light headaches, but research has clearly shown that recommended vaccines do not have associations with serious disorders, like autism.