Some literature that pertains to vaccines and autism is of the viewpoint that vaccines, or any vaccine component, has no correlation with autism. One of the most appropriate pieces of evidence is a study done by Frank DeStefano, Crisofer Price, and Eric S. Weintraub (2012). The methodology of this study is extremely thorough and eliminates many gaps in data from the design. For three groups of children (birth to three months old, birth to seven months, and birth to two years), the cumulative amounts of antigen exposure were calculated based on the children’s medical charts and compared with children that have already been diagnosed with autism (DeStefano, Price, & Weintraub, 2012). This was done in order to see if there was a greater amount of immunologic activity in the autistic children than in the control group (DeStefano, Price, & Weintraub, 2012). The discussion further draws the conclusion that there is no correlation between immunologic activity, vaccines, and autism, and goes on to suggest that the debate questioning whether vaccines cause autism has little evidence behind it because autism is known to be a genetic disorder that develops when a child is in the womb (DeStefano, Price, & Weintraub, 2012). Most of the focus does not pertain to the findings of the study, because the data presented speaks for itself: A majority is an evaluation of the verifiability of the study. Various weaknesses are pointed out and justified with real data pulled to show examples (DeStefano, Price, & Weintraub, 2012). According to DeStefano, Price, and Weintraub (2012), these weaknesses include but are not limited to: “take into account all of the antibody-stimulating proteins and polysaccharides in each vaccine… Admittedly, this approach assumes that all proteins and polysaccharides in a vaccine evoke equivalent immune responses.” This is justified by a statement just after the above quotation stating that the estimates calculated are “a valid relative ranking of the antigen content of vaccines” (DeStefano, Price, & Weintraub, 2012). Most of the other pieces of literature that do not support an association between vaccines and autism do not provide as detailed a discussion of the verifiability of the results.
MMR Vaccine Doses and Possible Independence From Autism
A handful of literature surrounding this highly debated issue focuses on a possible correlation between the measles, mumps, and rubella vaccination (MMR) and autism. One of the most well-advised analyses took place in Denmark in the 1990s (Madsen et al., 2002). All of the children born in Denmark during this decade were evaluated based on data from the Danish Civil Registry for the vaccines they received, particularly MMR, and whether they were diagnosed with autism (Madsen et al., 2002). The conclusion drawn from the data remains: “This disquisition provides three strong arguments against a causal relation between MMR vaccination and autism. First, the risk of autism was similar in vaccinated and unvaccinated children, in both age-adjusted and fully adjusted analyses. Second, there was no temporal clustering of cases of autism at any time after immunization. Third, neither autistic disorder nor other autistic-spectrum disorders were associated with MMR vaccination” (Madsen et al., 2002). The discussion of verifiability of results is not as extensive as DeStefano, Price, and Weintraub’s, but is sufficient and points out that weaknesses in the design include that there was no documentation whether the children with autism had a family history or if it was a regressive autistic disorder (Madsen et al., 2002). The last piece of literature discussing an association between the MMR vaccination and autism is an article by Dr. Francis Collins, the director of the National Institutes of Health and the lead research behind the Human Genome Project (2015). Dr. Collins (2015) introduces a scenario that determines whether children who have an older sibling with ASD are more likely to be diagnosed with autism. The answer to this question proved yes, but Collins (2015) included that the study also found children who had received the MMR vaccination were not more likely to be diagnosed. He goes on to denote that vaccines should be given not only because of the almost, in his opinion, nonexistent data supporting that vaccines cause autism, but that the illnesses contracted can be fatal if the proper vaccine is not administered (Collins, 2015).
Thimerosal’s Alarming Effects Despite Autism
Thimerosal is a topic for concern, as some scientists theorize it playing a role in triggering autism for those who are vaccinated. Brian J. Catton (2015) writes, “Thimerosal, a preservative found in several vaccines was created in 1927. [It] contains almost 50% mercury by weight and is broken down to ethyl-Hg hydroxide and ethyl-Hg chloride in aqueous saline solutions that can be toxic to human cells.” Thimerosal has not been shown to have any correlation with autism according to Catton’s data, but it has been removed from most vaccines anyway (Catton, 2015).
California Department of Developmental Services Data
Two investigations use a very particular data source: the California Department of
Developmental Services System (CDDS). Frank DeStefano and Robert T. Chen (2001) provide reason to doubt the data from this source. The scientists point out that over the amount of time the CDDS has existed, the diagnostic criteria for autism has changed and more people in the population are aware of and can recognize autism (DeStefano & Chen, 2001). Also, they point out that accurate numbers of autistic children in the state are hard to account for. “Trying to correlate changes in vaccination schedules and coverage, however, is very difficult on a state or national level because many other factors also changed over the same time period,” suggest Destefano and Chen (2001). Both studies (Dales, Hammer, & Smith, 2001) and (Schechter & Grether, 2007) provide justification for the use of this data despite the convincing argument proposed by DeStefano and Chen.
One study led by Drs. Dales, Hammer, and Smith (2001) recognizes that the CDDS warns their data is not sufficient for vaccines and autism studies. The methodology would be solid if a better data source than the CDDS was used, and the objective was to determine if an association exists between the MMR vaccine and autism. This was determined by evaluating children enrolled in kindergartens across the state from 1980-1994 and if they had received MMR and if they were diagnosed with autism (Dales, Hammer, & Smith, 2001). The conclusion states that the study would be more reliable if a link between autism diagnosis and immunization records existed for individual children and if the specific vaccine or series of vaccines was specified: “Data used in this study does not provide precise quantification of the percentages of children who received the combined MMR vaccine product versus separate injections of the measles, mumps, and/or rubella components” (Dales, Hammer, & Smith, 2001). This study did not support an association between vaccines, specifically MMR, and autism, though it was certainly not the most well-designed.
Another study conducted by Robert Schechter and Judith K. Grether used the CDDS as its data source (2007). This study focused more on the hypothesis that thimerosal can cause autism and used the data of children aged three to five years old from 1989-2003 (Schechter & Grether, 2007). The conclusion stated was synonymous with the other pieces of literature in this section, specifically that no decrease in the frequency of autism cases occurred despite the fact that thimerosal was removed from most vaccines during the period of time in which the study took place (Schechter & Grether, 2007). This study, like the other that used the CDDS as a data source, did not have hardly any justification of the use of the CDDS, but does point out that the CDDS was not designed for use in studies such as Dales, Hammer, & Smith’s and Schechter & Grether’s. (Schechter & Grether, 2007).
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