A large study published in The New England Journal of Medicine looked at 440,655
children born between 1991 and 1998, and showed NO difference in
autism rates between
children vaccinated with the MMR vaccine and those not vaccinated: http://www.nejm.org/doi/full/10.1056/NEJMoa021134.
Madsen KM, Hviid A, Vestergaard M, et al. A population-based study of measles, mumps, and rubella vaccination and autism. N Engl J Med. 2002;347(19):1477–1482.