Vaccinate your damn kids.'
There was a moment when I took the thimerosal-autism link seriously. Not in a "this must be true!" sense, but in the sense that there was a time when kids were getting more than acceptable levels of mercury in vaccines which seemed to correlate with the rise of diagonsed autism. It was a theory. A reasonable one. It seems that it wasn't a provable theory, and in any case the kids aren't getting that much mercury anymore.
I get that parents with autistic kids had thought they had found the cause. It doesn't seem that was correct.
In any case, vaccinate your kids.