KFF Poll: Lack of Trusted Provider and Social Media Use Linked to Vaccine Myth Belief
核心洞察
Adults without a trusted health care provider are nearly twice as likely to believe vaccine myths, including the false claim that MMR vaccines cause autism (搜索) (39% vs. 24%).
Frequent social media and AI chatbot users for health information show significantly higher rates of endorsing vaccine falsehoods, with differences persisting after controlling for demographics.
Parents who skip or delay childhood vaccines are about twice as likely to believe vaccine myths compared to those who keep children up to date (57% vs. 30% for the MMR-autism (搜索) myth).
A new KFF (搜索) Tracking Poll on Health Information and Trust reveals that Americans who lack a trusted health care provider, as well as those who frequently turn to social media or artificial intelligence chatbots for health information, are significantly more likely to endorse common vaccine myths—findings that carry implications amid declining childhood vaccination rates and rising measles (搜索) cases across the United States.
The survey, conducted May 7–31, 2026 among a nationally representative sample of 2,480 U.S. adults, examined public belief in four widely circulated false vaccine claims: that MMR vaccines cause autism (搜索) in children, that more people have died from COVID-19 (搜索) vaccines than the virus itself, that mRNA vaccines can alter DNA, and that measles (搜索) vaccines are more dangerous than measles infections.
The Protective Role of a Trusted Provider
Among adults who say they do not have a doctor or other health provider they trust to answer questions about their health—representing 16% of all adults—about 4 in 10 (39%) incorrectly believe it is either "definitely" or "probably true" that MMR vaccines have been proven to cause autism (搜索) in children, compared to 24% among those with a trusted provider. Similarly, nearly half (46%) of those without a trusted provider say it is "probably" or "definitely true" that more people have died from COVID-19 (搜索) vaccines than from the virus, nearly twice the share among those with a trusted provider (24%).
The connection between lacking a trusted provider and belief in vaccine myths holds even when controlling for factors such as age, race and ethnicity, education, partisanship, and insurance coverage. Adults without a trusted provider are much more likely to be uninsured than those with one (36% v. 7%), though KFF (搜索) notes that lacking a trusted provider could also reflect low trust in providers broadly rather than access issues alone.
Social Media and AI as Health Information Sources
Frequent use of social media and AI chatbots for health information is also tied to greater endorsement of vaccine falsehoods. Adults who use social media for health information at least weekly (26% of all adults) are more than twice as likely as those who never use social media for health to say the myth linking MMR vaccines to autism (搜索) is "probably" or "definitely true" (37% v. 16%).
A similar pattern emerges for AI use: 35% of adults who use AI chatbots at least weekly for health information endorse the MMR-autism (搜索) myth, compared to 20% among those who never use AI for health information. The relationship between belief in vaccine myths and use of social media or AI for health information remains significant even when controlling for demographic and political factors.
Parents and Childhood Vaccination Decisions
The poll finds a strong correlation between parents' belief in vaccine myths and their decisions about childhood vaccinations. Parents who report skipping or delaying recommended childhood vaccines are consistently at least 25 percentage points more likely than those who keep their children up to date to say vaccine myths are "definitely" or "probably true."
Specifically, 57% of parents who skip or delay vaccines believe or lean toward believing that MMR vaccines cause autism (搜索), compared to 30% among those who stay up to date. For the myth that more people died from COVID-19 (搜索) vaccines than the virus, the split is 55% versus 29%; for mRNA vaccines altering DNA, 52% versus 23%; and for measles (搜索) vaccines being more dangerous than measles, 43% versus 18%. This relationship remains significant even when controlling for age, education, and partisanship.
Exposure and Uncertainty: The Malleable Middle
Exposure to these false claims has remained fairly steady over the past several years, though the share who report hearing the myth that mRNA vaccines can alter DNA dropped by 9 percentage points since April 2025 (from 45% to 36%). Currently, 66% of adults say they have heard the MMR-autism (搜索) myth, 46% have heard the COVID-19 vaccine mortality claim, 36% have heard the mRNA-DNA myth, and 29% have heard the measles (搜索) vaccine danger claim.
While few adults are ardent believers—fewer than one in ten express definite belief in each myth—at least half fall into what KFF (搜索) terms the "malleable middle," saying each claim is either "probably true" or "probably false." The share who say it is "definitely false" that mRNA vaccines can change DNA has risen to 31% from 24% in April 2025, while the share saying it is "definitely false" that more people died from COVID-19 (搜索) vaccines than the virus has declined to 39% from 47% in June 2023.
A New Belief Typology
KFF (搜索)'s new analysis identifies five groups based on patterns of belief across the four false claims. A small share (8%) are consistent or leaned myth believers, while just over half (55%) are consistent or leaned myth deniers. About 3 in 10 adults (31%) fall into a "mixed middle" group, providing a range of true and false answers and lacking certainty on at least half of the claims.
This "mixed middle" group may represent an important focus for efforts to counter vaccine misinformation. Black adults (35%), Hispanic adults (40%), Republicans (44%), younger adults, and those without a college degree (36%) are all more likely than their counterparts to fall into this group. Notably, nearly half (45%) of parents who have skipped or delayed recommended vaccines for their children fall in the "mixed middle," indicating that these parents' decisions may be driven, at least in part, by uncertainty and confusion rather than firm conviction.
Adults who use social media for health information at least weekly are twice as likely to fall in the "mixed middle" as those who never use social media for health (41% v. 21%). The difference is smaller but still present for AI users.