I think what you're trying to say is not just a direct "stuff in vaccines triggers autism" but more to the point that if the lack of exposure to germs/diseases/pathogens can lead to an immune system response that can cause autism, then vaccines contribute to creating that "too clean" environment, by eliminating those diseases.

That's not how vaccines work, though. They create immunity through controlled exposure to the virus. If they were contributing to the "super clean" environment, then they would be preventing exposure.