Vaccines and Autism: CDC Study Says No Connection

Frank DeStefano, MD, MPH


April 12, 2013

Editorial Collaboration

Medscape &

In This Article

Knowledge, Attitudes, and Beliefs About Vaccines and Autism

Some parents are concerned that there is a link between vaccines (such as MMR) or certain vaccine ingredients (such as thimerosal) and autism. However, several large and reliable studies of MMR vaccine have been done in the United States and other countries.[3,4] None has found a link between autism and MMR vaccination. Furthermore, research[2] does not show a link between thimerosal in vaccines and autism. Although thimerosal was taken out of childhood vaccines in 2001, autism rates have continued to climb.

Although scientific evidence shows that vaccines do not cause autism, a 2012 HealthStyles survey showed that slightly more than 15% of parents are concerned that they do (LaVail K, Fisher A, CDC; unpublished data). Data from the survey found that 22.8% of parents are concerned that children receive too many vaccines at a single doctor's visit, and 22.8% of parents are concerned that children receive too many vaccines by the age of 2 years. The vaccines, they believe, can cause learning disabilities, such as autism. In another recent survey,[5] more than 1 in 10 parents of young children refuse or delay vaccinations in the belief that delaying vaccines is safer than giving vaccines according to the CDC-recommended immunization schedule. Children do not receive any known benefits from delaying vaccines. Delaying vaccines puts children at risk of becoming ill with vaccine-preventable diseases.