A new poll from health research firm KFF reveals that US adults who frequently seek health advice from artificial intelligence chatbots are more likely to believe anti-vaccine myths, such as the false claim that vaccines cause autism. The survey, conducted in May among a representative sample of 2,480 US adults, found a correlation between AI tool usage and belief in vaccine falsehoods, even after controlling for age, race, education, and political partisanship.
Key Findings on AI Users and Vaccine Misinformation
Among US adults who use AI for health information at least once a week, 35% believe it is “definitely or probably true” that the measles, mumps, and rubella (MMR) vaccine causes autism in children. In contrast, only 20% of those who never use AI for health hold this belief, while 29% of occasional AI users believe the myth. The false link between MMR vaccines and autism is a cornerstone of the anti-vaccine movement, which has gained traction since the COVID-19 pandemic and the appointment of Robert F. Kennedy Jr. as US health secretary.
The poll also found that 29% of frequent AI health users believe mRNA vaccines can alter human DNA—a scientifically untrue claim—compared to 20% of non-users. Additionally, 22% of frequent AI users think the measles vaccine is more dangerous than the measles virus itself, versus 15% of those who do not use AI for health.
Social Media’s Role in Spreading Misinformation
Consulting social media for health advice also correlated with belief in vaccine misinformation. KFF found that adults who use social media for health at least weekly are more than twice as likely as non-users to believe the MMR-autism myth (37% vs. 16%). Demographics differed: lower-income groups and those without college degrees were more likely to seek health advice on social media, while those in households earning over $90,000 annually or with college education turned more to AI tools.
The poll did not specify which AI models respondents used. Different chatbots produce varying levels of misinformation due to training data and company policies. Using AI for health advice mirrors broader search engine behavior: about 5% of all Google searches are health-related, and 77% of people use search engines to inquire about new diagnoses, according to a 2025 Georgetown University research paper.
Concerns Over AI and Public Health
Researchers and health officials have long worried about AI’s potential to spread misinformation. A March KFF survey found that about one-third of US adults seek health advice from AI. OpenAI acknowledged in a January blog post that “health is already one of the most common ways people use ChatGPT,” announcing a specialized ChatGPT Health tool. The persistence of debunked myths, such as the MMR-autism link—originally from a retracted 1990s Lancet study—underscores the challenge of combating misinformation in the AI era.
