The Association between the Measles, Mumps, and Rubella Vaccine and the Development of Autism: A Meta-Analysis

Autism is a childhood developmental disorder characterized by impaired social interaction, difficulty with verbal and nonverbal communication and limited activities. The root cause of autism is unknown. However it has been postulated that administration of the measles, mumps, and rubella (MMR) vaccine may be causally related to the development of autism. MMR vaccination is a requirement for entry into schools, so any increase in adverse events associated with the vaccine carries widespread public health importance. The primary objective of this study was to conduct a meta-analysis of the association between the MMR vaccination and the development of autism. The meta-analysis was limited to studies with an experimental design, unvaccinated control group, and odds ratio or relative risk as the effect measure. Both the fixed effects and random effects models were applied. A total of 29 studies were identified for possible inclusion in the meta-analysis. After applying the inclusion/exclusion criteria seven studies were included in the meta-analysis. The pooled treatment effect was weighted based on the width of the 95% confidence interval for each of the individual studies. The pooled effect measure for the seven studies was 1.052 (95% CI: 0.973, 1.138) (P=0.202). An association between the MMR vaccine and the development of autism was not found in this analysis. Public health initiatives should continue to support mandatory vaccination with MMR for entry into school and steps should be taken to eliminate any barriers to vaccination. Further epidemiological studies are needed to assess the root cause of autis