Autism Speaks: What kind of discussion do you have with parents who come to you fearing that a bad reaction to a vaccine – such as a febrile seizure – caused their child’s autism?"

"It’s so important to be respectful. While I explain that there is no evidence that vaccination causes autism, I try to listen and be open-minded. Currently, we can determine a specific cause of a child’s autism only 10 to 15 percent of the time. That lack of a clear explanation for their child’s autism can be frustrating and painful.

There are rare cases when the first signs of a brain disorder involve a child developing seizures and behavioral regression after a vaccine. However, the vaccine-associated fever didn’t cause the condition, it simply unmasked it – or triggered the first symptoms – just as a fever related to an actual infection could have done."