Don't I remember Thom saying that most European departments of health have studied this and found no specific connection?

I'm on several listservs distributing latest research results in psychiatry, mental health and evolutionary pscyhology, and autism is clearly the MOST RESEARCHED condition currently. Numerous methodologies are used across all age groups, including genetic studies, brain imaging studies, cognitive testing, etc. etc. Not once have I seen any mention of vaccination as a cause. In fact, there seems to be strong accumulating evidence that most of the diverse conditions on the autism spectrum can be traced to prenatal development (before any vaccinations, of course).

Hopefully Thom might take the time to check out this emerging understanding, here's one sample resource from about 2 years ago:

https://www.autismspeaks.org/science/science-news/direct-evidence-autism-starts-during-prenatal-development

A few sample snippets:

"A new study provides physical evidence that autism spectrum disorder (ASD) has roots in prenatal development. The research, supported in part by Autism Speaks, appears online in the New England Journal of Medicine.

"The researchers studied the donated post-mortem brain tissue of 11 children who had been diagnosed with autism and of 11 unaffected children. In 10 out of the 11 ASD cases, they found recurring patches of abnormal development in layers of the cerebral cortex that form during prenatal development. By contrast, they found the patches in just 1 of the 11 children unaffected by autism."

.....

"The physical evidence of early brain changes also backs a growing body of research linking increased risk for autism to genetically controlled processes and environmental influences that affect prenatal brain development."

"The most surprising finding was the similar early developmental pathology across nearly all of the autistic brains," says co-author Ed Lein, “especially given the diversity of symptoms in those with autism, as well as the extremely complex genetics behind the disorder.”

"The team found abnormal patches across the brain’s frontal cortex and temporal cortex. The frontal cortex is associated with complex communication and social abilities. The temporal cortex is associated with language.

"By contrast, the researchers found no abnormalities in the visual cortex. They note that visual perception tends to be unimpaired – sometimes even heightened – in individuals with autism."

As noted by several commenters, Thom Hartmann failed to research the issue of autism and vaccines before giving a full two hours of largely uncritical air time to promote Andrew Wakefield and his film "Vaxxed."

As a Ph.D. clinical psychologist, the Child and Adolescent Psychopathology course that I teach always includes an examination of the anxi-vaxxer movement, in an effort to inform students of the research regarding autism. The false information that Thom promoted by featuring Wakefield undermines everything that I try doing to educate my students regarding the actual science.

Where to begin? Thom has cited Snopes.com favorably in the past, so that's a good start. Consider the following:

http://www.snopes.com/medical/disease/cdcwhistleblower.asp

It's worth following the links in that article, which provide far more detail.

The film "Vaxxed" alleges a conspiracy of silence at the CDC. However, one must entertain the notion of a vast international conspiracy in order to account for numerous independent studies beyond the U.S. -- mainly in Scandanavian countries, including millions of children -- that have found no association between the MMR vaccine and autism.

While I could detail much more, the point is that Thom potentially has caused serious harm by providing Wakefield such an uncritical opportunity to spread misinformation.

I hope that Thom -- after doing some more careful research -- retracts explicitly on his radio show that naive and very wrong endorsement of Wakefield, just as Salon.com retracted Robert F. Kennedy, Jr.'s ant-vaxxer article some years ago.