It is one of the scariest things a parent can encounter.
Autism is not an easy thing to deal with and there is a lot of information out there, but not all of it is useful.
Dr. Christopher Ayers has dealt with autism quite a bit in his practice. He sorts out fact from fiction.
Autism is a developmental disorder in which children are lacking social interest, have speech delays, and are involved in repetitive interests/activities. There are usually symptoms in infancy, but it is not diagnosed until 18-24 months.
Unfortunately, there are no known ways at this time to prevent autism. There have been no scientific studies proving a link between vaccines causing autism.
Please bring up any developmental concerns with your pediatrician at your child's check up.