46% of Americans Are 'Unsure' if Vaccines Cause Autism. They Don't

A new Gallup poll shows that while Americans are confident in vaccines overall, they're still unsure on debunked claims about a link between vaccines and autism.
A woman with tattoos receives a vaccine.

Misinformation has a powerful half-life, particularly when it comes to public health. In the latest demonstration of this, a new Gallup poll shows that there’s still “substantial uncertainty” among Americans about whether vaccines cause autism, particularly among Republicans. Vaccines do not cause autism, and the study claiming they do has been debunked for a decade.

The poll, released by Gallup early Tuesday morning, surveyed 1,025 adults by telephone in all 50 states, and came away with an array of depressing results. The agency found that 84 percent of Americans say that vaccinating children is important, down from 94 percent in 2001. It’s part of a discernible slide in vaccine confidence: in a 2015 survey, Gallup found only 72 percent of the American public “strongly or somewhat” agreed that vaccines are safe, a higher rate of skepticism than many other wealthy nations. Those numbers might sound reassuringly high, but they aren’t: herd immunity depends on the vast majority of the population staying vaccinated, about 95 percent of the population in the case of measles. It’s a firewall, and a small crack can have outsized effects: the CDC says that 2019 saw the greatest number of confirmed measles cases since 1992.


Even more alarming are the statistics on the debunked link between vaccines and autism: 46 percent of those surveyed said they are “unsure” about whether vaccines cause autism, and 10 percent said they do. There’s been a “modest increase,” Gallup says, in the number of people who say vaccines cause autism, up from 6 percent in 2015. More reassuringly, the number of people who say vaccines don’t cause autism has also gone up, equally modestly, from 41 percent to 45.

Vaccines emphatically don’t cause autism, but the tail of that particular lie has been extremely long. A link between the MMR vaccine and autism was proposed in a deeply flawed 1998 study that was retracted in 2010. The lead author on the study, Andrew Wakefield, lost his medical license, though he’s had a long and profitable second act on the anti-vaccine circuit.

The Gallup survey also found that people’s views on vaccines and autism seem linked to both their education level and their voter affiliation. People with a post-graduate education were much more likely to say vaccines don’t cause autism than people with no college experience. But that doesn’t mean people with less education believe vaccines cause autism, according to Gallup:

Importantly, lesser-educated Americans are much more likely to have no opinion than to say they believe vaccines do cause autism. The percentage making the causal connection tops out at 12% among Americans with no college education, versus 5% of postgraduates.


Gallup also found “substantial partisan differences,” with 55 percent of Democrats saying vaccines don’t cause autism, versus 37 percent of Republicans. Before his election, Donald Trump suggested that vaccines cause autism, though he’s mostly remained mercifully quiet on the subject since his election, and even proclaimed, “The vaccinations are so important” back in April, at the height of one of the measles outbreaks last year.

Gallup suggested that, on the whole, “pro-vaccine public awareness campaigns” are working, educating most Americans on the benefits of vaccines. “On the whole, people accept that vaccines are less dangerous than the diseases they are meant to prevent,” Justin McCarthy, a media relations specialist at Gallup, told VICE.

That said, he added, “on the specific topic of autism, there are lingering uncertainties about a potential link between the two. We cannot say why there is uncertainty, but there have been studies that have been widely publicized though thoroughly debunked that claim some sort of relationship between the two–and these studies may have introduced some doubts that continue to linger.”

In other words, McCarthy suggested that the long-debunked studies that linked vaccines and autism created lingering doubt. There’s also a question, though, about how much coverage of the purported vaccine “debate” might contribute to those lingering doubts.

“I’m honestly torn about the media reporting on vaccines and autism,” said Alycia Halladay. She’s the Chief Science Officer of the Autism Science Foundation, which supports autism research and helps demystify autism treatments and identify pseudoscience. “The media has turned around and started getting facts correct, but I just worry that the word “vaccine” just ignites controversy.” As an example, she pointed to New Jersey, where the legislature struck down a proposal yesterday to remove religious exemptions for vaccines.

“This is something they should be doing,” Halladay said. “But the coverage of it just reminds people that there is a controversy and may cause people to yes, go online, curious as to why there is a controversy, and hit those websites and reignite any doubt.”

Halladay worries about a psychological theory called the “illusory truth effect.”

“It means that we believe false information if it is presented over and over again,” she said. “And perhaps the simple link between vaccines and autism, even if the statement says “vaccines do not cause autism,” is enough. It’s a complex issue, and our brains can handle 'vaccines cause autism' quicker than 'vaccines do not cause autism, it is a complex interaction of genetic and many environmental factors.' Cognitively, it’s just easier for people to link vaccines and autism, especially if the controversy just keeps on popping up over and over again.”

Beyond the possible effects of keeping the vaccine debate in the news, though, there’s also a vast network of organizations, funded by some of the richest people in the country, devoted to spreading misinformation about vaccine safety: Last month, for example, it was revealed that one of the biggest sellers of “natural health products” turned around and poured his millions back into funding the anti-vax movement. It’s almost as if a lie, when repeated long and loud enough, will start to sound to some people like the truth.