Other Offenders
There are probably multiple causes of autism. In addition to the genetic factor, several other possibilities have been suggested, such as pesticides and other environmental toxins, maternal autoantibodies, prenatal infections and medications, parental age and mental illness, and childhood yeast or viral infections. Because the list is so extensive, autism warrants more research—not only focused on its cause and possible prevention but in its treatment.

Every year the CDC says 30,000+ people in the US die from the Flu. What the CDC fails to say is that most of the people who died, really died from getting pneumonia because their immune systems were weakened by the Flu.
Vaccines are designed to promote a strong response from an individual's immune system. For infants, whose immune systems are fully developed, the effect of vaccines is even stronger. So, what happens when an infant gets the measles, mumps, rubella, chicken pox, tetnus, diptheria, hep B and polio vaccines all on the same day? The fact is no one really knows. The effects of vaccines have never been tracked in any trials beyond 6 weeks.
Autism isn't the only condition that's been increasing at an alarming rate over the past 20 years. Look at asthma, juvenile diabetes, ADD/ADHD, and more.
The head of the CDC recently admitted all of the studies it funded to prove vaccines don't cause autism were poorly designed. It's time to the right studies are done.