The debate over vaccines and autism is far from settled in the public eye, and now Rensselaer Polytechnic Institute (RPI) finds itself at the center of a heated controversy. The institute is standing behind Professor Juergen Hahn, who has been contracted by the Centers for Disease Control and Prevention (CDC) to investigate potential connections between childhood vaccinations and autism—a topic that continues to ignite strong emotions and divided opinions.
This month, the CDC announced its intention to award a no-bid, fixed-price contract to RPI for this research. If the project moves forward, Professor Hahn will lead the study aimed at exploring whether vaccines could be linked to autism spectrum disorder. This announcement has sparked immediate backlash from some members of the scientific community and within RPI itself.
Details about the contract’s funding amount and the timeline for completing the research remain unclear, adding to the uncertainty surrounding the project.
Experts in autism research, particularly those at Boston University’s Center for Autism Research Excellence, have expressed skepticism about the planned study. They point out that Hahn’s previous autism-related research has relied on relatively small sample sizes and that his findings have not been independently replicated—a critical step in validating scientific results.
Helen Tager-Flusberg, director of the BU center, described Hahn’s work as "fringe research," emphasizing that some of his most significant findings have yet to be confirmed by other scientists. She also criticized the limited number of participants in his studies, which can undermine the reliability of conclusions drawn.
For example, in 2017, Hahn announced the development of a blood test intended to identify autism. His study involved 149 individuals, about half of whom had been diagnosed with autism. According to Hahn, the test correctly identified over 97% of autistic participants. However, a similar study at Boston Children’s Hospital, which included a larger group of 416 individuals, found the blood test to be only 85% accurate. The researchers there noted the need for more extensive sampling and are currently tracking infants identified by the test to evaluate its predictive power over time.
Hahn has also investigated differences in gut microbiota between autistic and neurotypical children. In a study comparing 21 neurotypical children with 23 autistic children, he reported distinct differences in fecal matter composition. This led him to explore whether modifying gut bacteria could potentially alleviate autism symptoms or even serve as a form of treatment. However, Hahn himself acknowledged that factors like dietary habits and the small sample size might explain these observed differences, highlighting the complexity of such research.
Despite the criticism, Hahn and RPI defend the upcoming CDC-funded study. They argue that revisiting the vaccine-autism question is scientifically valid, especially when using new datasets and methodologies to either confirm or challenge previous findings. An RPI spokesperson noted that science is an evolving process, and referencing a large Danish study published earlier this year, they emphasized the value of re-examining complex issues to deepen understanding.
The Danish study, which analyzed data from over one million people, investigated whether aluminum in vaccines could be linked to autism, allergies, asthma, and around 50 other chronic conditions. The study concluded there was no association between aluminum exposure from vaccines and an increased risk of these health issues.
RPI maintains that Professor Hahn’s team is well-equipped to conduct this research with the necessary intellectual rigor and methodological precision, should the CDC contract proceed.
However, critics remain unconvinced. Tager-Flusberg expressed doubt about the qualifications of those leading the study, stating, "These are not the people who are the first names that come to mind in the field of autism. I would say these are not the people I would expect to be looking at this."
The rationale behind the CDC’s selection of RPI for this controversial study is not yet clear, especially given the agency’s recent struggles with public trust and internal controversies.
In addition to the CDC contract, Professor Hahn has submitted two separate proposals for funding under the government’s Autism Data Science Initiative. Neither of these proposals involves vaccines. One focuses on autism and co-occurring conditions, while the other explores microbiota transplant therapy for autistic patients. Hahn has not yet received word on whether these proposals will be funded, with announcements expected soon.
The controversy has even reached RPI’s alumni community. Some former students have urged the institute’s board of trustees to reject the no-bid CDC contract. Milo Trujillo, a postdoctoral researcher at Northeastern University and RPI alumnus, wrote a letter to the board, arguing that the supposed link between vaccines and autism has been thoroughly debunked. He warned that Hahn’s research could inadvertently lend credibility to vaccine skeptics, potentially fueling vaccine hesitancy.
Trujillo highlighted the real-world consequences of declining vaccination rates, including the resurgence of preventable diseases like measles, which can lead to unnecessary suffering and fatalities. He urged RPI to reconsider the contract for the sake of public health and the institution’s reputation.
Meanwhile, the CDC itself is navigating its own challenges. Recently, its Advisory Committee on Immunization Practices (ACIP) reversed a decision regarding the MMRV vaccine, which protects against measles, mumps, rubella, and chickenpox. Initially, the committee voted against recommending the MMRV for children under four due to concerns about febrile seizures—seizures associated with fever that, while not harmful to the brain, can be frightening for parents. They also voted to allow the Vaccines for Children program to cover the vaccine’s cost.
However, the following day, the committee reversed the decision about funding, citing confusion over the proposal’s wording. This flip-flop highlights the complexities and challenges in vaccine policy-making.
Typically, the chickenpox vaccine is given separately but during the same visit as the MMR vaccine. Some healthcare providers advocate for the combined MMRV shot because it reduces the number of injections children receive, which can improve compliance with vaccination schedules—especially in communities where follow-up visits are difficult.
The roots of the vaccine-autism controversy trace back to a discredited 1998 study by British scientist Andrew Wakefield. Wakefield manipulated data to suggest a link between the measles vaccine and autism, while simultaneously attempting to market his own version of the vaccine. His study, based on just 12 children—some without autism and some showing symptoms before vaccination—was exposed as fraudulent, leading to his medical license being revoked.
Despite this, the idea that vaccines cause autism has persisted in public discourse. Numerous studies since then have found no evidence supporting this claim.
The MMR vaccine is typically administered when children are between 12 and 15 months old, coinciding with the age when some children begin to show signs of autism, such as regression in speech, eye contact, and self-soothing behaviors. This timing has contributed to the misconception of causation. This form of autism, known as "regressive autism," remains poorly understood, with researchers exploring genetic and environmental factors. Statistically, regression tends to occur around 19 months—well after vaccination—but can sometimes appear as early as 15 months, which complicates the narrative.
So, here’s the question: Should we revisit a topic that the scientific community has largely settled, or does re-examining it with new data offer valuable insights? And what are the implications of funding such research in today’s climate of vaccine skepticism? Does this study risk lending undue credibility to debunked theories, or could it help reinforce public trust through rigorous science?
We’d love to hear your thoughts. Do you agree with RPI’s decision to proceed, or do you side with critics who warn of potential harm? Join the conversation and share your perspective below.
