VACCINES AND AUTISM

There is a strong debate regarding the possible link between childhood vaccinations and the subsequent development of autism.  Vaccinations that have received the most attention are the measles, mumps, rubella (MMR) vaccine and thimerosal-containing vaccines such as diphtheria, tetanus, pertussis (DPT or DT) vaccine.  The rising incidence and prevalence of autism has led some theories between the disorder and vaccines.  Vaccine-preventable diseases clearly still hold a presence in modern day society and the decision to opt out of MMR or other childhood vaccination schedules because of concerns regarding the development of autism should be properly evaluated with available evidence.


A study included a retrospective and prospective cohort and case-control studies looking at the relationship between vaccinations and disorders on the autistic spectrum (ASD).  The cohort studies included for meta-analysis reported negative findings in their individual investigations of MMR, Hg orthimerosal and autism, other ASD, or autism with regression.  The case-control studies included in the analysis all individually reported finding no evidence for an association between vaccination and ASD.  In all, the meta-analysis of five case-control and five cohort studies examine over 1 million child cases and found no evidence for the link between vaccination and risk of developing autism or autistic spectrum disorder.

The only review that suggests a link could not be excluded was that by Ratajczak, looking into the etiology of autism and concluded that it is multi-factorial, involving genetics and/or inflammation of the brain caused by a wide variety of environmental toxins, one of which maybe mercury.


As with any treatment, we must weigh the benefits and risks to determine future actions. While at the level of the individual avoidance of immunization may be seen as conferring lower risk by avoiding possible associated adverse events, the increase in parents deciding to take this course of action has substantially decreased overall immunity among populations, subsequently increasing the risk of catching potentially more serious infectious diseases.

An infected child serves as a vector, spreading diseases easily to others without vaccination.  The current outbreak of measles, which started in California, is a good prime example of the importance of vaccinations.   Thus, the risk incurred by not immunizing a child is increasing substantially as levels of immunization coverage fall.  In regards specifically to the fear of a child developing autism following immunization, the data consistently shows the lack of evidence for an association between autism, ASD and vaccination, regardless of whether the intervention was the MMR vaccine itself or one of its components, providing no reason to avoid immunization on these grounds.  Vaccination protects children from serious illness and complications of vaccine-preventable diseases which can include amputation of an arm or leg, paralysis of limbs, hearing loss, convulsions, brain damage, and death.