A meta-analysis of studies of the effects of measles, mumps, and rubella vaccines on the development of autism among children

Despite evidence from numerous sources, failing to demonstrate consistent evidence of autism due to measles, mumps, and rubella (MMR) vaccinations, parents continue to forego vaccinating their children against MMR due to fear that their children will develop an autism spectrum disorder (Baker, 2008). In 1998, Wakefield et al. concluded that MMR vaccines were causally associated with autism in children. Since then, the MMR vaccine has lost credibility and gained reticence from parents to vaccinate their children in the United States and Europe. Six years later, a meta-analysis done by Cochrane Collaboration provided evidence of no causal association between MMR vaccine and autism, and Institutes of Medicine (IOM) safety reviews failed to show a correlation between MMR and autism. However, this evidence has not been sufficient to eliminate the fear that MMR causes autism. Given that the 2004 Cochrane Collaboration meta-analysis is nearly eight years old, a new meta-analysis of primary studies on MMR and autism spectrum disorders was conducted. The meta-analysis included primary studies found in Elsevier, ERIC, Dissertations and Theses, Google Scholar, PsychInfo, ProQuest, PubMed, Scopus, and Web of Science. In addition, the authors searched journals related to health. In addition, unpublished primary studies were sought by contacting known researchers who studied MMR and autism. With the studies, effect sizes were calculated and a weighted mean determined. Study results indicated no causal evidence of MMR vaccination with development of autism, strengthening the results of the 2004 meta-analysis conducted by the Cochrane Collaboration.