I don’t know that they do.
I know of families where one of the kids was autistic so they didn’t give vaccines to the next kid. The next kid was still autistic.
Maybe in some kids autism is triggered by vaccines. I don’t think anyone really knows at this point.
I do think most people think there is a genetic component, but maybe something environmental triggers it.
I agree. I also think they should break up the MMR into separate vaccines. There's enough anecdotal evidence suggesting that this triple vaccine could be a trigger.