In 2025 the United States saw a large measles outbreak as childhood vaccination rates fell after the COVID-19 pandemic. More than 2,000 measles cases were reported across 43 states, the most since the disease was declared eradicated in 2000. Almost all cases occurred in unvaccinated people, and MMR coverage among school children was about 93%, below the 95% threshold often cited for herd immunity.
To examine connections between information sources and vaccine beliefs, researchers at Johns Hopkins surveyed 2,970 adults in August 2025; the study appears in the journal Vaccine. The survey asked where participants got news and health information and how they felt about the MMR vaccine. Most participants (87%) said they followed the news and 83% said the vaccine’s benefits outweighed the risks, but roughly one in six reported some vaccine hesitancy.
The analysis showed distinct patterns. People who regularly used “new right” digital outlets such as Breitbart, Newsmax and Zero Hedge were more than twice as likely to be vaccine hesitant compared with people who never used those outlets. Hesitant adults were also more likely to rely on non-authoritative health sources — for example, alternative health providers, social media health influencers and alternative newsletters such as Children’s Health Defense — while non-hesitant adults relied more on physicians, which appeared protective.
Hesitant adults had characteristic demographics: 62% were under age 44, they were more likely to be parents, and they tended to be racial minorities, lower-income and less educated. They also reported more conservative political views, identifying as Republican (39%) or Independent (33%), and were more likely to identify with the Make America Healthy Again movement (MAHA), 43% versus 27% for non-hesitant adults. The authors conclude that where and how people get information matters, and they recommend that public health communicators address these online sources when designing efforts to increase vaccination.
Difficult words
- outbreak — sudden increase of disease cases in area
- eradicate — to completely remove a disease or problemeradicated
- threshold — a level that triggers a desired effect
- herd immunity — population protection when many people are immune
- hesitancy — reluctance or doubt about accepting a vaccinevaccine hesitancy
- authoritative — coming from a trusted, expert and reliable sourcenon-authoritative
- outlet — a media channel or website that publishes newsoutlets
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- What steps could public health communicators take to address online sources that encourage vaccine hesitancy?
- The article lists demographic groups more likely to be hesitant. How could vaccination campaigns be adapted to reach these groups effectively?
- The study found that relying on physicians appeared protective. Do you think promoting physician communication is enough to reduce hesitancy? Why or why not?
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