>>4 Correlation is definitely not causation, though I think it's a good indication that something MAY be going on. Even so, from a biological perspective, vaccines causing autism seems ridiculous.
I'm also pretty sure there is a correlation between humans existing and stupid people. Thus we should get rid of all the humans to get rid of all the stupid people. Though obviously thats an extreme version I guess.
Even so, we honestly truly don't know everything that goes on when we treat people with drugs etc, we go through rigorous tests to try ensure saftey, but I think we have a pretty good idea that vaccines don't cause autism.