Vaccine myths are not new. They have circulated for decades, surviving retracted studies and countless public health campaigns. Now, a new poll suggests that, while relatively few Americans fully believe those falsehoods, many remain uncertain about them—a finding that suggests opportunities to counter vaccine misinformation.
The findings arrive amid declining vaccination rates, increasing numbers of vaccine-preventable diseases like measles, and significant upheaval in US vaccine policy. For example, vaccination coverage for the measles, mumps, and rubella (MMR) vaccine among US kindergartners during the 2024-25 school year was 92.5%, a decrease from the year before and below the national target of 95%.
As of last week, 30 measles outbreaks have been reported in the United States in 2026. That follows a record-breaking 48 outbreaks in 2025. Cases have climbed to 2,134, compared with 2,288 for all of last year. And the nation’s measles elimination status is in jeopardy.
Also, during the Trump administration, public health authorities have attempted to revise the childhood immunization schedule, slashed support for vaccine research, and spotlighted discredited claims about vaccines on official websites.
The poll includes a nationally representative sample of 2,480 US adults and was conducted May 7 through May 31.
The survey, published today, found that two-thirds of adults (66%) have heard the false claim that MMR vaccines have been proven to cause autism in children. Nearly half (46%) have heard the claim that more people have died from COVID vaccines than from the virus itself, and 36% have heard that mRNA vaccines can alter a person’s DNA. Twenty-nine percent have heard that measles vaccines are more dangerous than measles infection.
Fewer than 1 in 10 adults said they firmly believed any of the myths, but many expressed doubts. “When it comes to belief in these vaccine myths, more people are on the side of the truth, but we continue to find that at least half of people express uncertainty, falling in this ‘malleable middle,’” KFF analyst and lead author of the study, Alex Montero, MA, told CIDRAP News.
Within the malleable middle, nuances exist. The poll pinpointed five distinct groups that make up this group.
For example, consistent myth believers (1% of the public) believe all four vaccine myths and say that at least three out of four are “definitely true,” while those in the “mixed middle” (31%) give a range of true and false responses and at least half of the time provide a “probably” response in either direction. Consistent myth deniers (29%) say all four vaccine myths are false and at least three out of four are “definitely false.”
Hispanic and Black adults, Republicans, people without a college degree, and younger adults were more likely to belong to the mixed-middle group, “making them an important focus for those looking to counter vaccine misinformation and dispel confusion,” the analysts write.
The poll found a strong association between trust in healthcare providers and vaccine attitudes, with adults who have a provider they trust being less likely to believe vaccine myths.
Just under half of adults (46%) who do not have a trusted healthcare provider to answer questions about their health said it was “probably” or “definitely true” that more people have died from COVID vaccines than from COVID itself. That’s almost twice as many as those who reported having a trusted provider (24%).
Researchers noted that the relationship remained significant even after accounting for factors such as age, race and ethnicity, education, political affiliation, and insurance status.
Even among parents who are skipping or delaying vaccines for their children, larger shares express uncertainty than consistent, ardent belief, which may present an opening for those looking to dispel vaccine myths.
Alex Montero say:
“We’ve seen in our polling that healthcare providers are one of the most trusted sources of health and vaccine information among the public, and these latest findings show how lacking such a trusted source is linked with a willingness to endorse vaccine myths, which further underscores the role providers may play in this respect,” says Montero.
The survey also found that people who regularly use social media or artificial intelligence for health information were more likely to believe or lean toward believing vaccine myths. Thirty-seven percent of adults who use social media for health information at least weekly said the false claim linking MMR vaccines to autism was “probably” or “definitely true,” compared with 16% of those who never use social media for health information.
Parents who reported delaying or skipping recommended childhood vaccines were substantially more likely to endorse vaccine myths than were parents who keep their children up to date on vaccinations.
More than half of parents who delayed or skipped recommended vaccines believed or leaned toward believing that MMR vaccines cause autism (57% vs 30%), that COVID vaccines killed more people than the virus (55% vs 29%), and that mRNA vaccines alter DNA (52% vs 23%). More than 40% believed or leaned toward believing that the measles vaccine is more dangerous than measles (43% vs 18%). When the analysts controlled for factors like age, education, and partisanship, the relationship remained significant.
But a closer look at how parents responded to the poll suggests an opportunity to reach skeptical caregivers. “Even among parents who are skipping or delaying vaccines for their children, larger shares express uncertainty than consistent, ardent belief, which may present an opening for those looking to dispel vaccine myths,” says Montero.
