A 2011 study found that the higher the proportion of children receiving recommend vaccinations, the higher the prevalence of autism or speech/language impairment. Individually and collectively, the 2nd through 7th vaccine series in the first year of life have not been studied for rates of autism in children who received versus who didn’t receive the vaccine. For the 1st vaccine series, the Hepatitis B, a recently published study found that it was associated with a 3x increased risk of autism in boys during the study period. Scientifically, whether vaccines cause autism is still an open question. For more details, see Why is the vaccine-autism question far from answered?
The pursuit of the science to answer that question is hindered by many misconceptions. There is a common misconception that autism is just a normal form of social awkwardness that shouldn’t be considered an adverse health condition. In reality, individuals with autism are physically sick. Recent clinical investigations have identified numerous co-morbid disease states in children with autism. These include abnormal gastrointestinal function and inflammatory bowel disease, evidence of increased oxidative stress, severely altered serum chemistries, methylation disturbances, increased heavy metal burdens and microglial activation in the brain. These disease states are amenable to medical and nutritional interventions as reported by clinicians treating autism.
Another common misconception that autism is genetic. In reality, the momentum in science is towards an understanding of autism as an environmentally-triggered condition for which there might be a genetic susceptibility, but that most cases of autism are not caused by genetics (see Study debunks autism as a primarily genetic disorder). A significant number of top scientists and medical doctors are calling for research into environmental causes of autism including vaccines (See Top Scientists Calling for Environmental Research into Autism). Large genetics studies continue to find that inherited genes don’t cause autism (see Inherited Genes Don’t Cause Autism). A 2010 EPA study found that the cause of autism is environmental, and that the environmental cause occurred beginning with children born around 1988. An EPA study that autism has an environmental cause which began to occur with children born in 1988 (see EPA Study: Autism Boom Began in 1988, Environmental Factors Are Assumed).
There are several misconceptions regarding the epidemic increase in autism rates since the late 1980’s. Given that the vaccination schedule dramatically increased at about the same time as the epidemic increase in autism, these misconceptions are sometimes propagated by persons seeking to protect the vaccine program. Misconceptions on the increase in autism include:
- The misconception that there is no autism epidemic, there’s just been better diagnosis. This misconception states that children today are getting diagnosed with autism that in previous generations received mental retardation diagnoses. This “diagnostic replacement” was based on a 2002 study but after fundamental flaws were pointed out, the authors withdrew their conclusion and stated that diagnostic substitution did not appear to occur. Two other studies also reached the conclusion that diagnostic substitution did not occur, and the theory has been discarded but some Pro-vax adherents still propagate this misconception (see page 1 of Response to Dr. Ari Brown and the Immunization Action Coalition, which also includes a detailed scientific rebuttal of many of the talking points currently put forth by pro-vax adherents regarding autism).
- The misconception that the increase in autism rates is due to broadening of the definition of autism. In reality, an important study by the University of California-Davis found that autism increases cannot be explained by changes in doctors’ diagnoses and suggested that there must be an environmental cause to the real increase in autism. (see New Study: Autism Linked to Environment).
- The misconception that there has been no actual increase, that autism has always been with us but was undiagnosed in past generations. In reality, autism rates amongst adults are dramatically lower than in children less than 22 years of age (see EPA Study: Autism Boom Began in 1988, Environmental Factors Are Assumed). A recent UK study claimed that undiagnosed adult autism rates similar to diagnosed rates in children, but on further inspection the study was defining adult autism in an unusually broad manner (effectively, anyone with social awkwardness). The vast weight of scientific studies indicates that autism rates had a real increase in the late 1980’s, and that current autism rates in adults (undiagnosed + diagnosed) are significantly lower than rates amongst children.
Summary: the cause or causes of autism are not yet scientifically proven, so one cannot say with certainty that vaccines cause autism. However given that most vaccines have not been fully studied for autism and that one vaccine study has indicated a 3x increased risk of autism, the possibility of vaccine-induced autism is scientifically plausible.