By Maryanne Demasi at Brownstone dot org.

When an unpublished study from one of America's most respected hospital networks surfaced in the US Senate last month, it reignited a fierce debate in medicine: are vaccinated children healthier than unvaccinated children?

The study, titled "Impact of Childhood Vaccination on Short- and Long-Term Chronic Health Outcomes in Children," was introduced into the Congressional Record on 9 September 2025 during a Senate hearing on "The Corruption of Science."

Attorney Aaron Siri, who specialises in vaccine-related litigation, told lawmakers the research had been completed in 2020 by scientists at Henry Ford Health, but never published.

The reason, he said, was fear.

"These were mainstream, pro-vaccine scientists," said Siri. "But when their analysis showed higher rates of chronic illness among vaccinated children, they were warned that publishing it could cost them their jobs."

Once uploaded to the Senate website, the results were public - and damning. The Henry Ford team found vaccinated children had far higher rates of chronic disease than their unvaccinated peers.

The reaction was swift.

Vaccine defenders dissected the study line-by-line, accusing its authors of methodological errors and "fatal flaws." Henry Ford Health itself issued a statement calling the paper from its own infectious-disease chief "unreliable."

This analysis looks at the study, the controversy, and the criticism - and why this single dataset has become a lightning rod in the debate over scientific integrity.

Not a 'Fringe' Lab

Henry Ford Health is not a rogue institution. It's a century-old teaching hospital with over 30,000 staff, affiliated with Wayne State University, and known for pioneering research in infectious disease and public health.

The lead investigator, Dr Marcus Zervos, is a veteran infectious-disease specialist. During the Covid-19 pandemic, he was a regular on local news programs, promoting vaccination and defending public-health mandates.

His involvement gave the project an establishment credibility rarely seen in vaccine-safety research.

Zervos and his colleagues agreed to perform a comprehensive comparison of vaccinated versus unvaccinated children using the health system's electronic medical records.

For years, the Institute of Medicine had urged the CDC to conduct such a study using its Vaccine Safety Datalink. It never did. So, Henry Ford's data scientists decided to test the claim themselves.

What They Found

The researchers analysed records for 18,468 children born between 2000 and 2016. Of these, 16,500 had received at least one vaccine, while 1,957 were completely unvaccinated.

They tracked both groups for up to ten years, looking for chronic conditions - autoimmune, allergic, respiratory, neurodevelopmental, and metabolic disorders.

The headline result: vaccinated children had 2.5 times the rate of "any chronic disease."

The risk was four times higher for asthma, three times higher for atopic conditions like eczema and hay fever, and five to six times higher for autoimmune and neurodevelopmental disorders.

After 10 years of follow-up, 57% of vaccinated children had developed at least one chronic condition, compared with just 17% of the unvaccinated children.

Notably, the study did not find higher rates of autism, though case numbers were too small to draw meaningful conclusions.

Overall, the authors concluded that vaccine exposure was associated with an increased risk of chronic disease.

The study wasn't perfect; none of these large retrospective studies are.

The authors acknowledged potential confounding factors - unequal follow-up times, and the likelihood that vaccinated children, who see doctors more often, were more likely to be diagnosed.

To address this, they performed multiple sensitivity analyses, including restricting the sample to children followed for at least one, three, and five years, and excluding those with minimal visits.

But even after these corrections, the risk ratios ...