Where and how they choose to do so matters.
In the wake of America's worst measles outbreak since eradication, researchers at Johns Hopkins have traced a quiet but consequential line between where people seek information and whether they choose to protect themselves and their children. A survey of nearly 3,000 adults found that those who regularly consumed 'new right' media outlets were more than twice as likely to distrust the MMR vaccine — a pattern that held even after accounting for politics, income, and education. The findings arrive not as a condemnation of any political tribe, but as a reminder that the information ecosystems we inhabit shape not only our opinions, but our bodies and the bodies of those around us.
- Measles — a disease declared eradicated in 2000 — returned in 2025 with over 2,000 confirmed cases across 43 states, nearly all among the unvaccinated.
- Consumers of outlets like Breitbart, Newsmax, and Zero Hedge were more than twice as likely to express vaccine hesitancy, revealing that media diet may be a stronger predictor of health behavior than demographics alone.
- Vaccine-hesitant adults disproportionately turned to social media influencers, alternative health providers, and wellness newsletters rather than physicians — a fragmentation of trust with real epidemiological consequences.
- National MMR coverage has slipped to 93%, below the 95% herd immunity threshold needed to shield vulnerable populations, and cases have continued climbing into 2026.
- Public health officials now face a problem that more facts alone cannot fix: reaching people not through the loudest megaphone, but through the specific voices and channels those people already trust.
Last August, Johns Hopkins researchers surveyed nearly 3,000 American adults about their news habits and their feelings toward the MMR vaccine — a question made urgent by a measles outbreak that had already spread to 43 states, producing more than 2,000 cases, the highest count since the disease was eradicated in 2000. Almost every infection occurred in someone who had never been vaccinated.
What the data revealed was less about politics than about information. People who regularly visited outlets like Breitbart, Newsmax, and Zero Hedge were more than twice as likely to express hesitancy about the MMR vaccine, even after researchers controlled for other variables. The vaccine-hesitant group — roughly one in six respondents — skewed younger, were more likely to be parents, and disproportionately identified with the Make America Healthy Again movement. But the sharpest dividing line wasn't ideology or income. It was where they looked for guidance.
Non-hesitant adults were far more likely to trust physicians. Hesitant adults leaned instead on alternative health providers, social media influencers, and wellness newsletters. The study's lead author, Lauren Gardner, framed it simply: when nearly everyone is online every day, what matters is not whether people are consuming information, but which information, and through which voices.
The stakes are measurable. Childhood MMR vaccination rates have declined since the COVID-19 pandemic, and current school-age coverage sits at 93% — below the 95% threshold required for herd immunity. Cases continued rising into 2026. The challenge facing public health communicators is no longer one of information scarcity. People are not lacking facts; they are navigating competing realities shaped by the ecosystems they inhabit. Reaching the hesitant means entering those ecosystems — a task growing harder as they multiply and drift further apart.
Last August, researchers at Johns Hopkins surveyed nearly 3,000 American adults about where they got their news and how they felt about the measles-mumps-rubella vaccine. The timing was urgent. Measles cases had exploded across the country that year—more than 2,000 confirmed infections spanning 43 states, the highest number since the disease was officially eradicated in 2000. Almost every case occurred in someone who had never been vaccinated.
What the survey revealed was a sharp divide in how Americans consumed information, and how that consumption shaped their willingness to protect themselves and their children. People who regularly read outlets like Breitbart, Newsmax, and Zero Hedge—digital news sources with a strong conservative political lean—were more than twice as likely to express hesitancy about the MMR vaccine compared to those who never visited those sites. The pattern held even when researchers controlled for other factors. It wasn't just politics; it was where people chose to look.
The vaccine-hesitant respondents, who made up roughly one in six of those surveyed, shared other characteristics. They tended to be younger—62 percent were under 44—and more likely to be parents. They were disproportionately racial minorities, lower-income, and less educated. Many identified with the Make America Healthy Again movement. But the most striking difference between hesitant and non-hesitant groups wasn't their demographics or their stated political beliefs. It was their information diet.
Most Americans in the survey, 87 percent, said they followed the news regularly. Nearly everyone reported being online daily and consuming content across multiple platforms and outlets. The crucial distinction emerged in what researchers called "selective media engagement." Non-hesitant adults were significantly less likely to spend time on right-leaning digital news channels. More importantly, they were far less likely to turn to non-authoritative sources for health guidance—alternative health providers, social media influencers, wellness newsletters like Children's Health Defense. They trusted physicians instead.
Trust in doctors emerged as a powerful shield against vaccine hesitancy. The study, published in the journal Vaccine, suggests that as Americans have fragmented into different information ecosystems online, those ecosystems have begun to shape fundamental health decisions. Lauren Gardner, the study's lead author and director of Johns Hopkins' Center for Systems Science and Engineering, put it plainly: "When everyone is already engaging online, where and how they choose to do so matters."
The backdrop to this research is a steady erosion of vaccination coverage since the COVID-19 pandemic. Childhood MMR vaccination rates have declined nationwide. Current coverage among school children sits at 93 percent—below the 95 percent threshold needed to achieve herd immunity and prevent measles from spreading through vulnerable populations. Measles cases continued to rise through 2026, a trajectory that public health officials have struggled to reverse.
The study points to a problem that cannot be solved by simply providing better information. People are not starved for facts; they are drowning in them. The question is which facts they encounter, and through which voices. A person who spends their online time in one media ecosystem will encounter a different reality than someone in another, even if both are consuming news daily. Health communicators now face the challenge of not just correcting misinformation, but reaching people through the channels they actually trust—a task that grows harder as those channels multiply and diverge.
Citas Notables
Our work reveals a strong association between people's specific media habits and their attitudes towards vaccination. When everyone is already engaging online, where and how they choose to do so matters.— Lauren Gardner, director of Johns Hopkins' Center for Systems Science and Engineering
With public health becoming increasingly polarized, it's critical to understand people's attitudes about vaccines, and this work suggests people's media preferences play an outsized role in influencing those attitudes.— Amelia Jamison, assistant research scientist at Johns Hopkins
La Conversación del Hearth Otra perspectiva de la historia
So the study found that people reading certain outlets were twice as hesitant about vaccines. But surely lots of people read those outlets and still vaccinate their kids?
True. The study shows association, not causation. But the pattern is consistent enough that it suggests something real is happening in those information spaces—either the outlets are actively discouraging vaccination, or they attract people already skeptical, or both.
What strikes me is that hesitant people weren't avoiding news altogether. They were online constantly, just in different places.
Exactly. This isn't about ignorance or isolation. These are engaged people. They're just engaged in ecosystems where physicians aren't the trusted authority on health. Alternative providers and influencers are.
And that matters because physicians have actual training and accountability?
Yes, but also because physicians operate within a system of evidence and peer review. An influencer can say anything and face no professional consequence. The hesitant adults in the study weren't rejecting expertise—they were accepting a different kind of expertise.
So the fix isn't just better messaging from public health?
It can't be. You can't out-message someone's entire information diet. You'd need to either rebuild trust in physicians within those communities, or somehow change what gets amplified in those digital spaces. Neither is simple.