In my personal opinion, the argument that vaccines cause autism is tenuous, at best. The CDC had a list of studies done, and most declared there to be little to no association between vaccines and autism.
I personally think the number of reported cases of autism is on the rise not necessarily because there are more cases. I think it is because as more is being learned about the disease, more childhood disabilities that previously had no name are being classified as "autism spectrum disorder" if they bear any similarities at ALL to the developing definition of autism. It's done all the time. If there's no name for a specific condition, doctors call it what it most resembles until a better solution comes along. There are also levels within the autism diagnosis. There are a number of autistic people who are high-functioning in society, some so high-functioning that one may not even realize that they are clinically described as "autistic." I don't think the number of cases of autism is more severe than it was a few years ago.
I also think what everyone needs to remember is that correlation does NOT equal causation. No study can prove that vaccines cause autism because it's extremely complicated to control for genetics, environmental factors, and countless other outside influences that would mess with the results of the study. The best scientists can do is prove there is a correlation between vaccines and autism. But, I think that if you try hard enough, you can find correlation between any two things, so in my mind, correlation isn't a very strong argument.
With my neurological background, I'm more likely to accept that autism is CAUSED by early problems in the development of the brain and its intraconnections. I specifically liked a quote I found on Wikipedia (that was found in a Neuroscience scientific journal...I wouldn't use unsubstantiated quotes, people!) that said, "Autism appears to result from developmental factors that affect many or all functional brain systems, and to disturb the timing of brain development more than the final product." Those problems may be exacerbated by vaccines, but in my opinion, children that develop autism already had a biological propensity for it.
This may sound harsh, but I think in many ways vaccines have become a scapegoat on which parents can blame their childrens' autism. I can imagine how devastating it would be for a parent to discover his or her child has such a difficult condition. According to my limited knowledge of human nature, it seems that people experiencing a painful event initially want to blame it on someone or something rather than accept that it may have been caused by random chance or sometimes even their own choices. In addition, it seems that parents of children with disorders caused by genetics often feel guilty, since it was THEIR genetics that caused their child's disorder. It's easier and less painful to place the blame somewhere else.
I know this is a sensitive subject. This is the conclusion to which I've arrived after doing my own research and thinking about the issue myself. I reiterate what I said in my last post: parents have the right to choose what is best for themselves and their children. For me and my children, I feel the benefits of immunizations outweigh the risks. I urge every parent to develop an opinion on this and any other issue relating to the health and well-being of his/her children.