The idea that vaccines can lead to autism stems from a thoroughly disproven, later retracted 1998 study in The Lancet. The study’s British author Andrew Wakefield was banned from practicing medicine in the United Kingdom after authorities revealed he had accepted $675,000 from a lawyer intending to sue vaccine makers.
Since then, 14 major scientific studies have debunked this myth. Among those showing no link between vaccines and autism: The Journal of Autism and Developmental Disorders, The Journal of Pediatric Infectious Diseases, PLOS One and the Centers for Disease Control. Oh, also The Lancet itself.