 -- A well-known autism advocacy group, Autism Speaks, is urging parents to vaccinate their children amid a measles outbreak that has already reached 14 states and infected 102 people last month.

Rob Ring, chief science officer of Autism Speaks, released a statement today stressing that vaccines do not cause autism, and parents should vaccinate.

"Over the last two decades, extensive research has asked whether there is any link between childhood vaccinations and autism," he said in the statement. "The results of this research are clear: Vaccines do not cause autism. We urge that all children be fully vaccinated."

The myth began with a now-debunked 1998 study linking the MMR vaccine -- which protects against measles, mumps and rubella -- to autism. The British Medical Journal retracted the study in February 2010, and study author Andrew Wakefield lost his medical license.

An editorial published in the British Medical Journal following the retraction called Wakefield's study "fraudulent." Wakefield stood to gain money from his findings because he was involved in a lawsuit against the MMR vaccine, according to the journal. He denied any wrongdoing.

Another study purporting to show a link between the MMR vaccine and autism was published in a much smaller journal over the summer, spurring the #CDCwhistleblower hashtag and conversation. But it, too, was retracted. The journal said in a statement that the study author had "undeclared competing interests" and that the journal had "concerns" over the author's methods, analysis and conclusion.