The controversy that will not go away: Vaccines and autism

Abstract

It is generally accepted that the number of new autism diagnoses is increasing. It is unclear whether this is due to a true increase in cases, increasing awareness of autism spectrum disorders (ASDs), or differences in the methods used to diagnose these conditions and assess their prevalence. The burden of ASDs for families and communities is considerable both monetarily and emotionally. In the first few decades after autism was described, it was thought to be a consequence of bad parenting, particularly by the mother. Despite decades of research, a specific scientific cause or definitive treatment for ASDs remains elusive in most cases. This lack of evidence has led to much speculation about the etiology of ASDs. Early reports of associations between the MMR vaccine and autism have been shown to be based on flawed and perhaps fraudulent studies. Similarly, reports linking the mercury-containing preservative thimerosal with autism have been refuted by several rigorously conducted scientific studies. The third theory that vaccines either weaken or overwhelm the immature immune system in young children and lead to autism is also not supported by credible scientific data. Emerging research indicates the genetic underpinnings of ASDs, but a small, vocal minority of parent groups and even a few physicians and scientists continue to support the hypothesis that vaccines cause autism. Unsubstantiated media reports and litigation sponsored by some parent advocacy groups continue to keep the controversy alive. Vaccines have been phenomenally successful in eliminating diseases such as smallpox, measles, and polio. Fear of these deadly scourges has been replaced with concerns about vaccine safety among some members of the public. Declining vaccination rates have caused a reemergence of some of these diseases. In order to reestablish the public's trust in vaccination, it is imperative that rigorously researched scientific information on the issue of vaccines and autism is accurately collected and appropriately disseminated.