In a development with profound scientific and public-health implications, the CDC has quietly updated its longstanding position on vaccines and autism—acknowledging for the first time that the long-repeated lie “vaccines do not cause autism” has never been an evidence-based statement.
The shift represents a historic departure from the fraudulent claims of the past three decades.
Because the CDC has not yet publicly briefed the nation on the significance of this update, Dr. Peter McCullough, John Leake, and I (Nicolas Hulscher, MPH) held the press conference they did not, outlining the context, the history, and the evidence that brought us to this moment.
This historic reversal comes just three weeks after the McCullough Foundation Report: Determinants of Autism Spectrum Disorder—a 300+ study comprehensive review demonstrating convergent evidence that childhood vaccination is the most significant modifiable risk factor for autism.
A shift of this magnitude also reflects the persistence and courage of scientists, physicians, attorneys, journalists, and families who refused to abandon the truth. We recognize the indispensable contributions of Dr. Brian Hooker and his team at Children’s Health Defense, Dr. Sherri Tenpenny, attorney Aaron Siri, Del Bigtree and ICAN, Tony Lyons of Skyhorse Publishing, Gavin de Becker, Jackie Schlegel at Texans for Vaccine Choice, current HHS Secretary Robert F. Kennedy, Jr., Toby Rogers, thousands of parents who have seen their child regress with their own eyes, and countless more.
The Five Major Reports on Vaccines and Autism (1991–2025)
1991 — Institute of Medicine (IOM)
Key Finding:
”No data were identified that address the question of a relation between vaccination with DPT or its pertussis component and autism.”
2012 — Institute of Medicine (IOM)
Key Finding:
”The evidence is inadequate to accept or reject a causal relationship between diphtheria toxoid–, tetanus toxoid–, or acellular pertussis–containing vaccine and autism.”
2014 — HHS Agency for Healthcare Research and Quality (AHRQ)
Key Finding:
“A comprehensive review of the studies investigating the safety of routine childhood vaccines concluded that there was no evidence to accept or reject a causal relationship between DTaP and autism.”
2021 — HHS Agency for Healthcare Research and Quality (AHRQ)
Key Finding:
”The findings from the 2012 IOM report and the 2014 AHRQ report (based on the IOM) of insufficient evidence for an association between autism and DTaP/Tdap/Td remained unchanged. The 2021 update identified no new studies; the scientific evidence continued to be insufficient to support or reject a causal relationship between those vaccines and autism.”
2025 — McCullough Foundation Report: Determinants of Autism Spectrum Disorder
Key Finding:
A comprehensive review of 300+ studies found strong convergent evidence supporting a link between early childhood vaccination—particularly cumulative, clustered, and early-timed doses—and increased risk of autism and neurodevelopmental disorders. Of 136 vaccine-related studies reviewed, 107 inferred positive links, while none evaluated the safety of the full cumulative pediatric vaccine schedule. The report concluded that vaccination is the most significant modifiable risk factor for ASD.
This report was sent to HHS on October 28, 2025.
Why This Moment Is Historic
For decades, federal agencies asserted certainty where none existed. Families were dismissed. Physicians and researchers who raised concerns were maligned.
The CDC’s November 2025 update marks the first time a major U.S. health authority has formally recognized:
that its prior denial was not evidence-based
that infant vaccines have never been properly evaluated for autism causality
that mechanistic pathways—including neuroinflammation and mitochondrial vulnerability—require investigation
and that parental testimony deserves respect, not dismissal
With today’s shift, a window of opportunity has opened to protect future generations from debilitating neuropsychiatric disorders. At the McCullough Foundation, we are now planning a critical large-scale case-series study focused on children who were developing normally—and then regressed into autism following a battery of vaccinations. By systematically documenting these cases and analyzing shared clinical/molecular patterns, we aim to bring this decades-long debate to a definitive scientific conclusion. If you want to help accelerate this research, please consider supporting our efforts at: https://mcculloughfnd.org/products/donate-1
Epidemiologist and Foundation Administrator, McCullough Foundation
Support our mission: mcculloughfnd.org
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