KFF poll finds vaccine myths reach many Americans but convince few

by · News-Medical

A new KFF poll shows that most Americans do not firmly believe vaccine myths, but uncertainty remains widespread, and trusted health care providers may be key to closing the confidence gap.

In a recent tracking poll report published by KFF, public opinion researchers examined public exposure to common vaccine myths, beliefs surrounding these claims, and their relationship with trusted health care providers, health information sources, and childhood vaccination decisions among adults in the United States.

Background

Nearly two-thirds of adults in the United States have heard the false claim that the MMR vaccine causes autism, highlighting how widely vaccine misinformation is encountered.

Vaccine myths remain common despite scientific evidence and medical advice. Uncertainty surrounding these claims can shape public confidence in vaccination and may influence health-related decisions.

Doctors and other trusted health professionals are important sources for correcting misinformation, and the poll links trusted providers to lower endorsement of vaccine myths, even though people often seek health advice online. Poll data can help identify groups most likely to express uncertainty about vaccine information.

About the poll

Researchers at KFF (formerly Kaiser Family Foundation) designed and analyzed a nationally representative survey to examine public attitudes toward health information and common vaccine myths. Data were collected between May 7 and May 31, 2026, from 2,480 adults in the United States through online and telephone interviews conducted in English and Spanish.

Participants were recruited using both Address-Based Sampling and Random Digit Dial (RDD) sampling methods.

Individuals responding via prepaid mobile phone samples completed interviews either by telephone or via an online questionnaire delivered via Short Message Service (SMS).

To improve representation, the sampling strategy intentionally included greater participation from Hispanic and non-Hispanic Black adults and incorporated political affiliation within the Address-Based Sampling design.

Survey data were weighted using demographic benchmarks from the United States Census Bureau's 2025 Current Population Survey (CPS) and additional national population data.

Statistical weighting accounted for demographic characteristics, geographic distribution, internet use, and sampling design to ensure that the findings reflected the national adult population.

Poll results

The survey found that exposure to vaccine misinformation remained widespread among adults in the United States. The false claim that the MMR vaccine has been proven to cause autism in children was the most commonly recognized myth, with approximately two-thirds of adults reporting that they had heard or read this claim.

Exposure to most of these myths remained relatively stable compared with previous KFF Tracking Polls, although fewer adults reported hearing the claim that mRNA vaccines alter DNA than in the previous year.

Although many adults had encountered these false claims, relatively few expressed complete confidence that they were true. Instead, a large group fell into what researchers described as the "malleable middle." These individuals generally responded that vaccine myths were either "probably true" or "probably false," indicating uncertainty rather than firm belief or rejection. Across the four vaccine myths examined, at least half of the respondents showed some level of uncertainty. While larger proportions classified each claim as definitely false, fewer than half of adults did so for any individual myth.

The findings also showed that adults with a trusted health care provider are less likely to believe or be inclined to believe common vaccine myths than those without a trusted health care provider. This association remained significant even after controlling for differences in age, race or ethnicity, education, political affiliation, and health insurance status among respondents.

Additionally, the survey found that the sources of health-related information used by adults were associated with their beliefs about vaccines, and that adults who use social media as a source of health-related information at least once a week were more likely to believe false claims about vaccines than those who never use social media for health advice.

Similarly, regular users of Artificial Intelligence (AI) tools or chatbots for health information were more likely to believe myths linking the MMR vaccine with autism and claims that mRNA vaccines alter DNA.

Parents who skipped or delayed recommended childhood vaccinations, excluding seasonal COVID-19 and flu vaccines, were also considerably more likely to believe or lean toward believing all four vaccine myths, suggesting that uncertainty and confusion may be associated with vaccination decisions.

To better understand response patterns, researchers grouped participants by their beliefs regarding all four vaccine myths. Only a small proportion of adults consistently accepted all four myths, while more than half consistently or generally rejected them. However, nearly one-third belonged to a "mixed middle" group that combined true and false responses while expressing uncertainty on at least half of the questions. This group was more common among Black adults, Hispanic adults, Republicans, younger adults, individuals without a college degree, and those who regularly used social media or at least occasionally used AI for health information.

Nearly half of parents who reported skipping or delaying recommended childhood vaccines also fell into this mixed middle category, indicating that uncertainty rather than unwavering belief characterized many of their responses.

Conclusion

The findings demonstrated that exposure to vaccine myths remains common among adults in the United States, even though relatively few people strongly believe these false claims.

Many individuals expressed uncertainty, underscoring an important group that may benefit from accurate, trustworthy health communication.

These results emphasize the continuing importance of trusted medical guidance and reliable health information in addressing vaccine-related misinformation and public uncertainty.

Want to read later? Download your PDF copy by clicking here.

Journal reference: