For decades, parents searching for answers on autism and childhood vaccines found a clear statement from scientific authorities: vaccines do not cause autism.
But after a recent update on the US Centers for Disease Control and Prevention (CDC) website — directed by US Health and Human Services Secretary Robert F. Kennedy Jr. — confusion and concern have surged among medical leaders, parents and autism advocates.
The updated CDC page now states:
“Scientific studies have not ruled out the possibility that infant vaccines contribute to the development of autism.”
This shift has triggered strong backlash from doctors and autism organizations, who emphasize that the claim is scientifically false and based on outdated, debunked ideas.
Global Experts Reject Claims Linking Vaccines to Autism
More than 25 years of research across multiple countries consistently shows the same conclusion:
➡️ Childhood vaccines are not linked to autism.
Over 40 large-scale studies involving 5.6 million people have found no evidence of any connection, said Dr. Sean O’Leary from the University of Colorado and the American Academy of Pediatrics’ infectious disease committee.
Dr. Alycia Halladay of the Autism Science Foundation explains that these studies — conducted in Denmark, Sweden, Finland, Israel, Japan and more — analyzed vaccination patterns and autism diagnoses in massive populations.
“Vaccines remain the most heavily studied environmental factor in autism, and there is no link whatsoever.”
Following the CDC’s new statement, over 60 major medical and autism organizations demanded a reversal, calling the update misleading and scientifically inaccurate.
Where Did the Autism-Vaccine Myth Begin?
The false belief that vaccines cause autism originated from a 1998 study by British doctor Andrew Wakefield, which claimed a connection between the MMR (measles, mumps, rubella) vaccine and autism.
However, the study was later exposed for:
- extremely small sample size
- no control group
- financial conflicts
- fabricated data
The paper was retracted in 2010, and Wakefield lost his medical license.
Yet the myth spread rapidly and became rooted in public anxiety.
Parents seeking answers about their child’s diagnosis often want a cause — and vaccines became an easy scapegoat.
Dr. Halladay explains:
“It preys on parents’ fears and convinces them they can prevent autism by avoiding vaccines. It’s taking advantage of vulnerable families.”
Since Wakefield’s claims went viral, dozens of real scientific studies tried to replicate his findings — and every single one disproved them.
So What Actually Causes Autism?
Autism is complex and varies widely from person to person. It’s now better diagnosed and understood, contributing to rising prevalence.
In 2022, 1 in 31 US children was diagnosed by age 8.
Genetic factors
Autism is highly genetic.
- Over 250 genes are associated with autism.
- In 15–20% of cases, a single gene mutation can be identified.
- In many others, multiple genes interact.
These genes are active during fetal brain development, influencing how nerve cells communicate.
Environmental factors
Certain non-genetic conditions can increase autism likelihood, such as:
- maternal illness during pregnancy
- premature birth
- high parental age
- fever during pregnancy
- metabolic disorders like gestational diabetes
However, vaccines are not in this list. In fact, staying vaccinated during pregnancy helps protect both mother and fetus.
Dr. Halladay adds:
“Getting diseases like measles poses far greater risk than any mild vaccine reaction.”
Why the CDC Update Is Concerning to Experts
Autism organizations criticized the CDC update because the new statement did not come from CDC scientists.
Instead, it appears to have been added by HHS administrators, bypassing scientific review.
This breaks trust, Halladay said:
“We’ve always told parents to rely on CDC guidance. Now the site includes information that isn’t supported by science.”
Worldwide health authorities — Europe, the UK, Canada, Mexico — continue to state clearly that vaccines do not cause autism.
Where Parents Should Get Reliable Vaccine Information
Trusted sources for accurate, evidence-based information include:
- Autism Science Foundation
- Autism Society of America
- Autism Speaks
- American Academy of Pediatrics
- American College of Obstetricians and Gynecologists
But most importantly:
“Trust your pediatrician,” Halladay says. “They know your child and can give the best guidance.”
