These Wall Street Journal health blog excerpts make it clear that the decision Federal vaccine court special masters was very clear cut. This was not a hard call, the scientific evidence is overwhelmingly against the vaccine-autism beliefs (emphases mine):
After careful consideration of all of the evidence, it was abundantly clear that petitioners’ theories of causation were speculative and unpersuasive. Respondent’s experts were far more qualified, better supported by the weight of scientific research and authority, and simply more persuasive on nearly every point in contention.
I concluded that the evidence was overwhelmingly contrary to the petitioners’ contentions. … The numerous medical studies concerning these issues, performed by medical scientists worldwide, have come down strongly against the petitioners’ contentions.
[P]etitioners’ experts tended to assign greater weight to speculative conclusions offered by the investigators involved in the studies than did the investigators themselves. Petitioners’ experts also urged reliance on a few carefully selected sentences from particular articles which, when considered in the proper context of the referenced articles, did not support the propositions advanced by the witnesses. Moreover, because petitioners’ experts relied on a number of scientifically flawed or unreliable articles for several important aspects of their causation theory, their testimony on those aspects of their offered theory could not be credited as sound or reliable. Finally, petitioners’ experts made several key acknowledgments during testimony that rendered their proposed theory of vaccine causation much less than likely.
The third opinion emphasizes that the petitioner's own experts, under examination, contradicted the belief that autism arises from immunization.
This won't be the end of the autism-vaccine meme of course. It long ago became a matter of quasi-religious belief rather than something amenable to data or reason. It will, however, make it very hard to press these arguments in the court system. It's not the judgments alone, it's the ferocity and clarity of the opinions that will make a difference going forward.
Update 9/20/09: Good f/u article on the decision. My favorite line:
... Among those expressing shock and disappointment was Rebecca Estepp, the mother of an autistic child, who is one of the claimants and the national manager of the advocacy group Talk About Curing Autism. "It's tough when you're taking parent support calls and you hear the same story day after day," she told the Wall Street Journal. "When does anecdotal evidence become enough?"Her question isn't a new one, especially in a society where belief, emotion and science so often conflict. For scientists, the answer to Estepp's question is never.
Thousands of years of anecdotal stories about witches causing disease didn't make it true.