In a surprising and controversial move, the U.S. Centers for Disease Control and Prevention (CDC) has quietly revised the language on its official vaccine safety webpage in a way that suggests uncertainty about the long-established scientific consensus that vaccines do not cause autism. This change, which emerged without broad public notice, echoes claims promoted by Health Secretary Robert F. Kennedy Jr., a known vaccine skeptic who has long questioned vaccine safety despite overwhelming scientific evidence to the contrary.
The update has sparked immediate and strong criticism from public health experts and scientists who warn that the CDC’s new language undermines decades of rigorous research and could have dangerous public health consequences. Michael Osterholm, an epidemiologist at the University of Minnesota, described the revision as a “tragedy,” emphasizing that it rejects well-established evidence proving no causal link between vaccines and autism. He further warned that such misinformation could erode public trust in vaccination programs, ultimately leading to fewer people getting vaccinated and preventable deaths among children.
Historically, the CDC’s vaccine safety page has been clear and definitive, citing extensive research that disproves any connection between vaccines and autism. However, the recent revision, which appears to have been made around November 20, 2025, now casts doubt on this conclusion by stating that the claim “vaccines do not cause autism” is not entirely evidence-based and suggesting that studies supporting a link have been ignored by health authorities. This equivocation is a stark departure from the agency’s previous position and contradicts the findings of numerous high-quality studies conducted over the past 27 years.
Since 1998—the year when a now-discredited and fraudulent study initially raised fears about vaccines and autism—researchers in seven countries have conducted more than 40 large-scale studies involving over 5.6 million individuals to investigate any potential connection. None of these studies have found credible evidence to support a causal link. For example, a major 2019 study involving more than 657,000 children specifically examined the measles, mumps, and rubella (MMR) vaccine and found no association with autism incidence. Susan J. Kressly, president of the American Academy of Pediatrics, reiterated this point emphatically, stating, “There is no link between vaccines and autism. Anyone repeating this harmful myth is misinformed or intentionally trying to mislead parents.”
The CDC’s new webpage also mentions that officials will begin investigating early childhood vaccinations and autism, a move that further fuels skepticism about vaccine safety despite the existing body of evidence. This language suggests that the agency is reopening questions that have been answered definitively by the scientific community, thereby potentially sowing confusion among parents, healthcare providers, and the public.
Brian Lee, an epidemiologist at Drexel University’s Dornsife School of Public Health, expressed serious concerns about the impact of the CDC’s revision on public trust. He remarked, “It will be hard for the public to trust anything the CDC has to say after this.” This sentiment highlights the potential damage to the credibility of one of the nation’s most trusted public health institutions at a time when public confidence in vaccines is critical, especially amid ongoing efforts to combat infectious diseases.
The CDC has not yet responded publicly to requests for comment regarding the change. The lack of transparency and communication about the revision has only intensified worries among scientists and health officials that the agency may be succumbing to political pressures or misinformation campaigns that undermine evidence-based public health policies.
This development comes at a critical moment when vaccines remain one of the most effective tools for preventing serious infectious diseases and protecting public health. The introduction of doubt about vaccine safety on an official government platform risks reversing the progress made over decades in increasing vaccination rates and reducing disease outbreaks.
The broader context of this controversy includes ongoing debates and misinformation surrounding vaccines, often fueled by social media, celebrity endorsements of anti-vaccine views, and politicization of public health measures. Robert F. Kennedy Jr. has been a prominent figure in promoting vaccine skepticism, and the CDC’s recent website changes appear to align with his narrative, despite the scientific community’s consensus to the contrary.
The consequences of disseminating misleading information about vaccines are far-reaching. Vaccine hesitancy can lead to lower immunization rates, which in turn increase the risk of outbreaks of preventable diseases such as measles, mumps, and whooping cough. These outbreaks can cause serious illness and death, particularly among vulnerable populations such as infants, the elderly, and immunocompromised individuals.
Experts warn that undermining confidence