A newly published study is being widely circulated, purportedly showing a link between vaccines and autism. A closer look at the methods, the journal, authors, and funders reveal a different story. The study “Vaccination and Neurodevelopmental Disorders: A Study of Nine-Year-Old Children Enrolled in Medicaid” does not show a relationship between vaccines and autism.
The paper can’t conclude anything about vaccinations or neurodevelopmental disorders. Yet it’s been amplified by RFK Jr. and his colleagues, who have profited off of anti-vaccine disinformation for decades in their latest attempt to undermine decades of data that show there is no causal relationship between vaccinations and autism.
Coincidentally, this paper was published Friday, January 24, 2025, just in time for the Senate hearings for RFK Jr’s potential confirmation as HHS Secretary, which began January 29. The timing seems intentional: legitimize anti-vaccine claims to aid his installation in our Federal leadership.
Serious Methodological Flaws
This paper is a prime example of correlation does not equal causation. It’s an observational study—data are “observed” for patterns. The data are not controlled, so you can’t assess how one variable (vaccines) impacts or even relates to the other variable (neurodevelopmental disorders or NDDs).
More importantly, the methods have serious flaws.
Their data set is Medicaid billing claims for children in Florida from 1999 to 2011. In short, these are receipts for Medicaid payments for qualifying health services. The authors compared billing codes related to vaccination medical visits and those that may or may not be related to diagnoses for NDDs, including autism spectrum disorder (ASD).
The authors fail to analyze, address, or even acknowledge serious confounding factors:
- Parents who vaccinate their children are more likely to seek healthcare. That means those kids are also more likely to be seen by healthcare providers to evaluate and diagnose NDDs. In contrast, parents who do not vaccinate their children often do not go to healthcare providers regularly or seek “practitioners” who offer services not covered by Medicaid (naturopaths, homeopaths, etc). If parents aren’t bringing their children to the doctor, they aren’t going to be diagnosed with ASD or related disorders.
- The authors ignore the improvements in the recognition and diagnosis of NDDs following the publication of the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV-TR) in 2000. The DSM-IV-TR clarified how to identify and diagnose ASD based on expanded criteria, resulting in increased ASD rates from recognizing cases with less stereotypical presentations. Why did the authors mention this change but not correct for it? They didn’t even refer to baseline rates of ASD after this clarification. If you’re curious, population-level ASD prevalence went from 1.16% in 2007 to 2.00% in 2011, the same magnitude as what the authors “show” vaccines cause autism.
- There was no correction for health conditions that predispose someone to NDDs. Their pitiable “analysis” of preterm birth data omits comorbidities linked to preterm birth, familial history of NDDs, and other factors known to be related to NDDs.
- The population is children enrolled in Florida’s Medicaid program, a specific geographic and socioeconomic group with unique characteristics. Low-income families with limited resources may not have access to specialists for complex medical issues. That means you can’t generalize to the broader population with more consistent healthcare access even if the data were usable.
- There is no information about how many and which vaccines were administered. The information comes from general billing codes for healthcare visits linked to vaccinations, which can’t confirm actual vaccine administration. The authors write that unvaccinated children are entirely unvaccinated, but they assume that based on a lack of Medicaid billing codes. Absence of evidence is not evidence of absence - perhaps the family was not on Medicaid when the children were vaccinated, then qualified for and applied for Medicaid? The data set is irrelevant.
The Journal Is Owned By An Anti-Vaccine Organization Founded By The Editor-In-Chief
It may not surprise you that the “journal” is not a credible scientific journal. James Lyons-Weiler, the Editor-in-Chief, founded it through his company, IPAK-EDU LLC. Lyons-Weiler has long made false claims about COVID-19 vaccines and vaccines broadly and has openly state[d] that he's rescuing “wrongfully retracted” papers.”
He and the other editors are notorious anti-vaccine activists with something important in common. See if you can spot it.
- Lyons-Weiler serves as the journal’s Editor-in-Chief and is a listed author at Children's Health Defense (CHD).
- Brian Hooker is Chief Scientific Officer for Children's Health Defense and editor of another anti-vaccine journal.
- Peter McCullough is a former cardiologist who had his medical license revoked for anti-vaccine rhetoric. He is an author for Children's Health Defense.
- Mary Holland is a lawyer and the CEO of Children's Health Defense.
- Russell Blaylock is a retired neurosurgeon and author at Children's Health Defense.
- Paul Thomas is a former pediatrician whose license was suspended in 2021. He has close ties with Children's Health Defense and has stated that he would “be okay not vaccinating his grandkids.”
RFK Jr and the Children’s Health Defense is the common thread. It is the same organization that made 23.5 million dollars in 2022 promoting false claims about vaccines, with RFK Jr receiving over $500,000 and Mary Holland $180,000 directly from CHD that year.
The Authors Have A History Of Writing Flawed Studies Undermining Vaccines
Anthony Mawson is the first author, supposedly the President of Chalfont Research Institute, a non-profit with no website and two employees: Anthony and his co-author Binu Jacob.
Mawson has a very suspicious CV in which he lists himself as a reviewer for multiple journals outside his scope of expertise, and has no training in infectious disease or biomedical science.
In 2017, these two authors published a similar article about the vaccination status of homeschooled children and NDD and autism spectrum disorder (ASD) in Frontiers of Public Health, which was retracted. It was then published by The Journal of Translational Science (JTS), only to be again retracted. JTS is a predatory journal that solicits manuscripts from unqualified people and does not have peer review.
That article was blasted for flawed methods, conclusions, and authorship. The cast of characters around Mawson illustrates the bias of the paper. For example, Brian Ray, founder of the dubious National Home Education Research Institute, is also a co-author of the retracted paper. (Note: Retraction Watch is an invaluable resource).
It is apparent that Mawson and Chalfont are hired research guns paid to lend credibility to shoddy methods and conclusions inspired by the groups funding the research.
Funded By A Long And Lucrative Histories Of Anti-Vaccine Rhetoric
The Funding Statement reads: “This research was funded by the National Vaccine Information Center (NVIC.org). The publication cost of this study was partially offset by The National Vaccine Information Center (NVIC.org) and by IPAK (ipaknowledge.org).”
If you’re not familiar, The National Vaccine Information Center is a notorious anti-vaccine organization. The Institute for Pure and Applied Knowledge (IPAK) conveniently owns the “journal” that publishes the study and provides funding. That’s definitely not a conflict of interest, right?
The Timing Of Publication
The article was conveniently published days before the Senate confirmation hearings for RFK Jr. as HHS Secretary. We need public health leaders who shape policy informed by high-quality research with rigorous scientific standards, not cherry-picked by those with ideological agendas to push and hired guns with shoddy methods.
This “study” was published by a cadre of anti-vaccine activists, funded by anti-vaccine money, in an anti-vaccine outlet, authored by a scientist-for-hire with a record of paper retractions for anti-vaccine disinformation. The veneer of legitimacy the anti-vaccine movement tries to fabricate is a tactic to gain power, influence, and momentum.
We are at a critical juncture of whether objective reality and robust evidence will be tossed aside from conspiracy theories, power, and money. If RFK Jr. and his dangerous anti-science rhetoric is legitimized, their actions will cause irreparable harm to all of us.
Source: study “Vaccination and Neurodevelopmental Disorders: A Study of Nine-Year-Old Children Enrolled in Medicaid” Science, Public Health Policy and the Law
Andrea Love, Ph.D.
Andrea Love, PhD, is a biomedical scientist and award-winning science communicator with a PhD in microbiology and immunology. In addition to her full-time career in life sciences biotechnology, she is the Founder of ImmunoLogic, a science education organization. She is also the Executive Director of the American Lyme Disease Foundation and writes about science and health topics for a variety of media outlets.
