By Stephen R. Anderson, Ph.D., BCBA-D 

April 28, 2025 

Introduction

As a psychologist and behavior analyst who specializes in autism, I am often asked if vaccines cause autism. This has become a concern of some parents who, understandably, want to keep their children healthy and safe. The prevalence of misinformation has begun to erode public confidence in the value of childhood vaccines.

In this article, I want to explain where the belief that vaccines cause autism came from, and what research have shown.

Where Did the Idea Come From?

The fear that vaccines might cause autism started with a paper published in 1998 by a British doctor named Andrew Wakefield. His study suggested a link between the measles, mumps, and rubella (MMR) vaccine and autism. However, there were several major problems:

• His study only included 12 children, which was far too small to draw any real conclusions.

• Investigations later showed that Wakefield had serious conflicts of interest (he was being paid by lawyers who wanted to sue vaccine companies).

• Other researchers could not find the same results when they tried to repeat his study.

• In 2010, Wakefield lost his medical license because of ethical violations and misconduct related to this research.

The original paper was retracted by the medical journal that published it – meaning they officially said it should not be trusted. In spite of this, the misconception that vaccines cause autism persists and recent comments made by the Secretary of Health and Human Services has further fueled speculation.

What Does Credible Research Indicate?

Since 1998, many large, well-designed studies have looked at whether vaccines are linked to autism. They have consistently found no link. Here are some examples:

• A study in Denmark followed over 650,000 children and found that the MMR vaccine did not increase the risk of autism.
  Denmark Study – Journal of Internal Medicine (2019)

• A review of 10 different studies, covering millions of children, concluded there was no relationship between vaccines and autism.
  Review of Studies (Vaccine 2014)

• Research has also shown that the timing of the rise in autism diagnoses matches better awareness and changes in how doctors diagnose autism, not vaccine schedules.

Why Does This Belief Persist?

Even though science shows no link, fear has stuck around for several reasons:

• Parents often notice signs of autism around the same age children get their vaccines (12-18 months). This can make it seem like the vaccine caused it, even though the symptoms were developing earlier.

• Misinformation spreads quickly on social media.

• Autism is complex. While we know that genetics account for up to 80% of cases, scientists are still researching the causes. It’s natural to look for simple explanations when answers are uncertain.

Why Vaccines Are Important

Vaccines protect children (and adults) from serious diseases like measles, which can cause brain damage or death. Thanks to vaccines, many deadly diseases have become rare.

When fewer children get vaccinated, diseases can return. For example, the U.S. saw outbreaks of measles in 2019 because vaccination rates dropped in some communities. In 2025, there was another outbreak of measles, and three deaths were reported.

Final Thoughts

It is understandable to have questions and worries when it comes to your child’s health. The good news is that decades of research around the world have shown clearly: Vaccines do not cause autism.

Vaccines keep children safe. Autism is a condition that begins before birth, likely due to a combination of genetic and environmental factors – not vaccines.

Reliable information is also available from trusted organizations like the Centers for Disease Control and Prevention (CDC) and the Autism Science Foundation.

About the Author

Dr. Anderson received his Ph.D. in Developmental and Child Psychology from the University of Kansas. Until January 2, 2024, he served as the Chief Executive Officer of The Summit Center and continues as a member of the staff. He has served as Adjunct Assistant Professor at a number of colleges and universities including the University of Kansas, Northeastern University and the State University of New York at Buffalo and Buffalo State University. He has published journal articles, book chapters, and one book on the education and treatment of people with autism or other developmental disabilities.