You may have seen recent headlines reporting that the CDC has changed its website: the statement “Vaccines do not cause autism” has been modified so that the CDC now says that the claim is “not an evidence-based claim because studies have not ruled out the possibility that infant vaccines cause autism.” Here it is if not. The American Medical Association, like me, feel very disappointed and concerned about the dangerous consequences to public health this could cause if it increases mistrust.

I'm livid in fact. I felt a blog post coming on as soon as I saw it...

For many healthcare professionals and parents this represents a dramatic shift. So it's inevitable that people may feel concerned by this — for how this might affect vaccine confidence, and whether we can still reassure patients (or their parents) that vaccines are safe. Once again, our jobs are made harder by agencies and politicians that know nothing of what it's like on the ground in clinics.

The good news: there is still a robust, large body of high-quality scientific evidence showing no causal link between vaccines and autism. The recent wording change on the CDC website merely reflects politics and a philosophical stance and does not reflect new evidence. The scientific consensus has not changed. What has changed is the messaging — likely for political or ideological reasons, rather than as a response to new data.

What the Evidence Actually Shows

Large-scale studies and meta-analyses

A 2014 meta-analysis reviewed 10 epidemiological studies (five cohort studies and five case-control studies), involving over 1.25 million children in cohort studies and nearly 10,000 in case-control studies, and found no association between childhood vaccination and autism spectrum disorder (ASD). For example, the pooled data gave an odds ratio (OR) ≈ 0.99 (95% CI 0.92–1.06) for vaccination in general, and a similar non-significant OR for MMR vaccination or exposure to thimerosal.

Numerous individual large-scale population studies support the same conclusion. For instance, a population-based study of MMR vaccination and autism found no increase in risk among vaccinated children.

Reviews of the scientific literature consistently conclude: despite decades of research, no credible evidence demonstrates that vaccines, or any components of vaccines (e.g., preservatives such as thimerosal), cause autism or increase the risk of ASD.

Why early concerns were overturned

The widespread fear linking vaccines (especially the combined MMR vaccine) to autism originates largely from a now-discredited 1998 paper by Andrew Wakefield. That paper has since been fully retracted, and Wakefield was struck off the medical register after investigations revealed serious misconduct.

Subsequent high-quality studies did not replicate his findings — instead consistently showing no link. Over 5 million children in different countries have now been included in peer-reviewed research on this topic.

Autism is now understood to be a complex neurodevelopmental condition with strong genetic contributions and multifactorial environmental influences — but rigorous research has repeatedly excluded vaccines as a causal factor. Thus, the prevailing expert view — endorsed by multiple professional bodies and researchers — remains that vaccines are safe and that there is no causal link to autism.

Why the CDC Statement Change Is Misleading — and What It Means

As of November 2025, the CDC’s revised webpage now says “the claim ‘vaccines do not cause autism’ is not an evidence-based claim because studies have not ruled out the possibility that infant vaccines cause autism.”

the change was not based on new research — no new data were cited. Rather, the update appears to stem from changes in agency leadership and direction; critics say the decision reflects ideology rather than science. Numerous public health bodies, autism advocacy groups, and experts have swiftly criticised the change, warning it may fuel misinformation, undermine decades of public health progress, and erode trust in vaccines.

In other words: the change is a communication change, not a new scientific conclusion. The science remains clear — vaccines have repeatedly been shown not to cause autism.

Why this matters for us - as health care professionals who are administering vaccines (and some people reading this who are trainers in the field too)

As a vaccinator — whether in occupational health, sexual health, travel health, paediatrics, or routine adult immunisation — this shift in public messaging may lead to increased hesitancy among patients (or their parents). People may ask us direct questions like: “Is it true the CDC now says vaccines might cause autism?” or “If even the CDC isn’t sure, how can I trust vaccines?”. If we remain silent or unprepared, we risk undermining confidence — not only in individual vaccines but in immunisation programmes generally. We hold a frontline role in maintaining public confidence and trust.

Practical Strategies — What to Say (and Do) in the Clinic

Here are some evidence-based suggestions for handling the “vaccine-autism” question in clinical practice:

Acknowledge the concern — without panic

Start with empathy: “I can see why you’d be worried — the recent change by CDC has understandably raised confusion.” Then clarify: “However, the change is in how the message is framed — not because of new scientific findings.”

Use clear, simple language + evidence

“Multiple large, high-quality studies involving millions of children have found no link between vaccines and autism.” “Important reviews / meta-analyses consistently show no increased risk — whether for MMR, thimerosal-containing vaccines, or other childhood immunisations.” “The early study that first raised concerns was discredited, retracted, and its author lost his licence.”

Explain what autism is (briefly) — and what we do know

“Autism is now understood as a neurodevelopmental condition with strong genetic and complex environmental factors. Research shows vaccines are not among them.” This helps shift the focus away from vaccines and toward what we do understand about autism’s origins — without speculation.

Reassure about the benefit–risk balance of vaccines

Remind parents / patients that vaccine-preventable diseases — measles, rubella, pertussis, hepatitis B — remain serious, sometimes life-threatening. Not vaccinating because of misinformation can lead to real harm; not only to the individual but to community health (herd immunity).

Be honest about uncertainty — but contextualise it

It’s honest to say: “In science, nothing is ever 100% — but right now, the best and largest body of evidence shows no link.” Contrast that with the enormous evidence for vaccines’ safety and effectiveness.

Refer to trusted sources and encourage informed discussion

Have up-to-date information at hand (e.g., evidence summaries from professional bodies, systematic reviews - see below for some links).

Encourage patients/parents to ask questions, express concerns, and discuss — but guide them through the evidence.

If needed, offer to send written info or links (some listed below) so they can review at home.

Support peer and family-centred decision making

Especially for parents of children with neurodevelopmental concerns, acknowledge their desire to protect. Emphasise that vaccination can provide protection with extremely low risk. And that if they are in any way now blaming themselves for allowing vaccination of their child that coincidentally later was diagnosed with autism, that this is not the reason. Encourage them to involve their autism specialist if relevant — and reassure them that vaccination does not interfere with autism diagnosis or treatment.

A call for calm, science-based communication — especially from us

The recent change in the CDC’s communication does not reflect new science. Rather, it reflects a shift in institutional messaging — potentially driven by political pressure.

Yet as front-line vaccinators — and as educators of other healthcare professionals — we have a unique and vital role. With clarity, empathy, honesty and science-based reassurance, we can help preserve trust in immunisation. We must not allow a historical doubt — fueled by messaging shifts — to derail decades of progress in preventing disease. Instead, we can use this moment to reaffirm what the science shows, support informed choices, and advocate for evidence-based public health.

References and further links

Gabis, L. V. (2022). The myth of vaccination and autism spectrum. European Journal of Pediatrics & Neurology.

Immunize.org. (2025). MMR vaccine does not cause autism. MMR & Autism – Evidence Summary.

What To Know About the CDC’s Baseless New Guidance on Autism and Vaccines.

Madsen, K. M., et al. (2002). A population-based study of measles, mumps, and rubella vaccination and autism. New England Journal of Medicine.

Taylor, L. E., Swerdfeger, A. L., & Eslick, G. D. (2014). Vaccines are not associated with autism: A meta-analysis of epidemiological studies. Vaccine, 32(29), 3623–3629.

he Journal PLoS Biology. (2025). Vaccines work… and do not cause autism. PLOS Biology. (See literature reviews cited on autism-vaccine connection.)

The Johns Hopkins Bloomberg School of Public Health. (2025). Vaccines Do Not Cause Autism — The Evidence Explained.