Autism Is NOT Caused By Vaccines

There’s a persistent myth out there that vaccines cause autism. It’s a claim that’s been repeated, debated, and shared countless times, but it’s simply not true. The scientific evidence is clear—autism is not caused by vaccines.

To understand where this idea came from, we have to go back to the late 1990s, when a research paper alleged a link between the MMR vaccine and autism. The study’s claims were picked up by media around the world and, understandably, caused alarm for many parents. But what didn’t reach the headlines as loudly was what came next: the study was quickly discredited. Its methods were deeply flawed, it relied on a tiny sample size, and crucial data had been misrepresented. Eventually, the journal that published it issued a full retraction, and the lead author lost his medical license.

But myths, once out in the open, are incredibly resilient. The idea persisted, fueled by celebrity endorsements, misinformation, and the natural desire to protect one’s loved ones. Despite repeated scientific studies finding no link between vaccines and autism, the myth stubbornly refuses to die.

Let’s look at what the evidence actually says. Dozens of large-scale studies from countries around the world—encompassing hundreds of thousands of individuals—have examined whether vaccines, including those containing thimerosal, a mercury-based preservative, increase the risk of autism. All have found the same answer: there’s no association. The Centers for Disease Control and Prevention, the World Health Organization, and every reputable medical body agree—vaccines do not cause autism.

So what do we know about autism? Research shows that autism is a complex neurodevelopmental difference with both genetic and environmental influences, most of which occur well before a child ever receives a vaccine. Genetic factors play a major role, and studies involving twins and families bear this out. There’s also emerging evidence that things like advanced parental age and certain pregnancy complications may increase autism likelihood. Vaccines do not appear on this list.

So why does this myth linger? Part of it comes from the timing—autism symptoms often become noticeable around the same age when children receive routine vaccines. Correlation, however, is not causation. Just because two things happen close together in time doesn’t mean one caused the other. Human brains are wired to look for patterns, and sometimes that wiring can lead us to the wrong conclusions.

The consequences of ignoring scientific evidence are not abstract. When vaccination rates fall because of fear, diseases like measles, which were once nearly eliminated, can resurge. These diseases are not just uncomfortable; they can be life-threatening, especially for those who cannot be vaccinated for medical reasons.

At the end of the day, rejecting the myth that vaccines cause autism isn’t just about defending science—it’s about protecting one another. Vaccines save lives, and autism deserves understanding, not blame placed on life-saving medicine. Let’s move forward with empathy, clear thinking, and a commitment to truth.