On November 19, 2025, the Centers for Disease Control and Prevention (CDC) quietly revised its ‘Autism and Vaccines’ webpage. The updated version now asserts that the statement “vaccines do not cause autism” is “not an evidence-based claim because studies have not ruled out the possibility that infant vaccines cause autism.”
For parents of autistic children and for those who already feel anxious about vaccines, this is not just a minor technical clarification. It sounds like: “Maybe vaccines really do cause autism, and no one told us.”
As a psychiatrist who works with autistic youth and their families at all stages of life, I worry this language misrepresents the science and adds emotional burden to families who are already under a lot of stress.
What Vaccine Evidence Currently Indicates
The vaccine–autism question is not new. It has been extensively studied for over 20 years through large, well-designed research across various countries.
A few examples:
- A 2014 meta-analysis pooling data from over 1.2 million children and nearly 10,000 autism cases found no link between vaccines (including MMR), thimerosal, or mercury exposure and autism.
- In 2019, a nationwide Danish cohort study of 657,461 children found that the measles–mumps–rubella (MMR) vaccine did not increase the risk of autism, did not “trigger” autism in high-risk children, and did not cause clustering of cases after vaccination.
- A 2025 Danish registry study of over 1 million children again found no increased risk of autism or 49 other chronic conditions in vaccinated children, including those who received aluminum-containing vaccines.
Additionally, independent reviews and summaries from the National Academy of Medicine, Immunize.org (a nonprofit organization that provides up-to-date vaccination information and advocates for policies that improve access), and academic vaccine-safety centers have consistently found that the epidemiologic evidence does not support a link between vaccines and autism.
Autism advocacy and scientific organizations, including the Autism Science Foundation, have publicly criticized the new CDC webpage for misrepresenting this body of work.
There has been no new, high-quality study proving that vaccines cause autism. What changed is a single federal webpage.
“You Can’t Prove a Negative,” and Why This Confuses Parents
The updated CDC language relies on a familiar but misleading idea: Because science cannot definitively rule out a link in every child, saying “vaccines do not cause autism” is not considered “evidence-based.”
But in medicine, we rarely work with 100% certainty. Instead, we ask:
- Are the studies large and well-designed?
- Do the results match across various populations and methods?
- If a risk exists, is it large enough for us to notice it?
When numerous independent studies involving millions of children fail to find an increased risk, the evidence-based conclusion is not we can’t say. It’s: if any risk exists, it is so small that it has not appeared despite extensive, careful searching.
We apply that standard to medications, procedures, and everyday health choices. Using a stricter, unfair standard only for vaccines — specifically regarding autism — doesn’t truly protect families. It only causes confusion.
How Vaccine Confusion Plays Out in the Exam Room
For my patients and their parents, this change is not just theoretical.
- It fuels guilt. Parents of autistic children already ask, Was it my fault? Reopening the vaccine question, without new evidence, only worsens that pain.
- It damages trust. Families who previously received reassurances might now feel deceived. This mistrust can extend to other areas of care, including ADHD treatment, sleep medications, and even routine checkups.
- It increases hesitancy. Siblings of autistic children already have lower vaccination rates. Suggesting that the science is “unsettled” is likely to deepen hesitancy and raise the risk of measles (which can be fatal or lead to lifelong complications) and other preventable infections.
Lost in this noise is what autistic children and adults truly need: early identification, personalized support, and communities that see them as whole people, not as “vaccine injuries.”
What I Tell Parents Now
When families ask me about the CDC update, I usually focus on three points:
- The overall evidence remains the same. The large, thorough studies that reassured us last year are still around today. No new, rigorous study has challenged that.
- Autism is complex — and vaccines are not among the causes. Current research centers on genetics, prenatal and early brain development, and other biological and environmental factors, not routine childhood vaccines.
- Skipping vaccines carries immediate, clear risks. We understand what occurs when vaccination rates decline: preventable diseases come back, and the most vulnerable children often suffer first.
Parents deserve honest science, clear language and practical support when making difficult decisions for their children. The CDC’s revised wording may be framed as ‘caution,’ but for the families I see, it’s creating confusion and emotional strain without offering any new clarity.
