By the summer of 2025, measles had returned to the United States in a way not seen since the disease was declared eradicated twenty-five years earlier. More than 2,000 cases spread across 43 states. Children were hospitalised. Public health officials scrambled. And a team of researchers at Johns Hopkins began asking a question that seemed, on its face, almost too obvious to bother studying: did the news people were watching have anything to do with it?
The answer, it turns out, is yes. Emphatically so.
In a survey of nearly 3,000 US adults conducted last August, researchers at Johns Hopkins’ Center for Systems Science and Engineering found that people who regularly consumed “new right” media outlets, think Breitbart, Newsmax and Zero Hedge, were more than twice as likely to believe the risks of the MMR vaccine outweighed its benefits. Twice as likely. That figure held even after adjusting for political affiliation, demographics, and a dozen other variables that might plausibly explain the gap. The study is published in the journal Vaccine.
What makes the finding awkward is that it isn’t really about health information at all. It’s about general news habits.
The Passive Exposure Problem
Previous research had already established that seeking health advice from social media influencers or alternative health practitioners correlated with vaccine hesitancy. That’s perhaps not surprising. But the Johns Hopkins team found that the strongest correlate wasn’t where people went looking for health information; it was what they were already reading every morning over breakfast. Passive exposure to politically-charged news coverage, it seems, shapes vaccine attitudes before people ever type “is MMR safe” into a search bar.
“Our work reveals a strong association between people’s specific media habits and their attitudes towards vaccination,” said Lauren Gardner, who directs the Center for Systems Science and Engineering at Johns Hopkins. “Our findings suggest that when everyone is already engaging online, where and how they choose to do so matters.”
The study surveyed 2,970 adults. About 83% believed the vaccine’s benefits outweighed its risks, but the remaining 17%, roughly 1 in 6 respondents, were categorised as hesitant. That hesitant group skewed younger (62% under 44), was more likely to be lower-income and less educated, and was considerably more likely to identify with the Make America Healthy Again movement: 43% of hesitant adults claimed MAHA affiliation, compared to 27% of those who were not hesitant. Hesitant adults were also more likely to be parents, which is perhaps the detail that concentrates the mind most. Nearly everyone in the survey was online daily, and nearly everyone consumed news across multiple platforms. The difference wasn’t who was online; it was where they went once they got there.
The Numbers Behind the News
The researchers quantified things carefully. Engaging with alternative health newsletters (such as those published by Children’s Health Defense) was associated with about a 39% increase in the odds of hesitancy. Getting health information from social media influencers raised those odds by roughly 41%. Alternative health practitioners pushed the figure up by around 70%. But none of those reached the magnitude of the “new right” media association, which produced an adjusted odds ratio of just over two. Relying on a physician for health information, by contrast, emerged as the strongest protective factor in the whole analysis. That old-fashioned variable, seeing an actual doctor, matters more than any digital intervention the researchers could identify.
The context in which all of this is playing out makes the findings harder, not easier, to act on. Childhood MMR coverage among US schoolchildren sits at around 93%, just below the 95% threshold generally considered necessary for herd immunity. Vaccination rates declined during and after the COVID-19 pandemic, partly because of missed appointments, partly because of a surge in hesitancy that public health researchers are still trying to fully characterise. And the political environment has, to put it mildly, not helped: since 2025, the federal government has restructured the CDC’s advisory panel on immunisation, while several states have loosened requirements for non-medical vaccine exemptions. Even without measuring their direct effects, the researchers found indirect ones; only 40% of US parents, according to a separate poll, believed federal public health agencies were operating on scientific grounds.
“With public health becoming increasingly polarised, it’s critical to understand people’s attitudes about vaccines,” said Amelia Jamison, an assistant research scientist at Johns Hopkins who studies health communication and co-authored the paper with graduate student Samee Saiyed. “This work suggest people’s media preferences play an outsized role in influencing those attitudes.”
What the Data Cannot Settle
The study has limits. It’s cross-sectional, which means it captures a snapshot, not a trajectory, and it cannot establish causation; people who are already vaccine-hesitant might simply be drawn to media that confirms their views, rather than having their views shaped by the media they encounter. The survey was conducted in English and recruited through an online panel, which skews the sample in ways that matter. And the researchers acknowledge that their model explains correlation, not mechanism.
Still. Two thousand measles cases in a country that had eradicated the disease. Childhood coverage below the threshold needed to keep outbreaks from spreading. A 17% hesitancy rate that concentrates among younger parents, precisely the group currently making vaccination decisions for the next generation of children. And the strongest single predictor of hesitancy being not a conspiracy theory someone sought out, but a news outlet someone happened to plump for. If public health messaging is going to do any good at all in that environment, it probably cannot confine itself to the question of what to say. It may also need to reckon with where anything gets heard.
Source: Jamison AM et al., “MMR vaccine hesitancy in a polarized information ecosystem,” Vaccine, 2026
Frequently Asked Questions
Does watching right-wing news actually cause vaccine hesitancy, or do people who are already hesitant just prefer those channels?
The Johns Hopkins study cannot settle that question, because it is cross-sectional rather than tracking people over time. Both explanations are plausible, and they probably reinforce each other; sceptical people may gravitate toward outlets that validate their doubts, while those outlets may deepen the scepticism of people who were originally open. What the data do establish is a strong statistical association, independent of political affiliation, that remains after adjusting for demographics.
If a doctor’s advice is so protective, why aren’t more people getting that advice?
Access to primary care is uneven in the United States, and the study found that hesitant adults were more likely to be lower-income and less educated, groups that face greater barriers to routine medical care. There is also a trust dimension: the same political environment that shapes media consumption may also erode confidence in physicians as neutral sources. The survey found only 40% of US parents believed federal public health agencies were operating on scientific rather than political grounds.
Is the US at risk of losing its measles elimination status?
Possibly, though that determination would rest with the CDC and the World Health Organization. The United States was declared measles-free in 2000, but the 2025 outbreak was the largest since elimination, with more than 2,000 cases across 43 states. Childhood MMR coverage sits at around 93%, below the 95% threshold considered necessary for herd immunity, and several states have recently made it easier to obtain non-medical exemptions from vaccination requirements.
Why does the MMR vaccine still generate so much hesitancy when the autism link was debunked decades ago?
The debunked 1998 paper is one thread in a much larger fabric. The researchers found hesitancy correlated most strongly with general news consumption patterns rather than specific anti-vaccine beliefs, suggesting the current wave of doubt is less about a single discredited claim and more about a broader erosion of institutional trust, one that has accelerated since the COVID-19 pandemic and been reinforced by politically-polarised media coverage of public health events.
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