evidence: Vaccines are not associated with autism or developmental delay. [...] Vaccines Are Not Associated With Autism: An Evidence-Based Meta-Analysis of Case-Control and Cohort Studies [...] In a review of literature on immunizations and autism, an overwhelming majority of studies concluded that there is no causal association between the MMR vaccine and autism. Also, no convincing evidence was found to support an association between the vaccine preservative thimerosal and autism. In addition, no evidence was found to support the use of chelation therapy in autism.