In 1998, Dr. Andrew Wakefield, a British gastroenterologist, described a new autism phenotype called the regressive autism-enterocolitis syndrome triggered by environmental factors such as measles, mumps, and rubella (MMR) vaccination. The speculative vaccination-autism connection decreased parental confidence in public health vaccination programs and created a public health crisis in England and questions about vaccine safety in North America. After 10 years of controversy and investigation, Dr. Wakefield was found guilty of ethical, medical, and scientific misconduct in the publication of the autism paper. Additional studies showed that the data presented were fraudulent. The alleged autism-vaccine connection is, perhaps, the most damaging medical hoax of the last 100 years.