People who follow “new right” media outlets are more than twice as likely to be vaccine-hesitant compared to those who never engage with those outlets, a new Johns Hopkins University study finds.

Researchers surveyed nearly 3,000 adults in 2025, as measles cases hit record highs in the United States, asking participants about their sources for news and health information and how they felt about the measles-mumps-rubella, or MMR, vaccine. The findings revealed how specific media habits are strongly associated with attitudes toward vaccines.

The study found:

Hesitant adults were more likely to rely on non-authoritative sources for health information, like alternative health providers, social media health influencers and alternative health newsletters, such as Children’s Health Defense.

People who regularly engaged with “new right” media outlets, meaning digital news outlets with a strong conservative political bias including Breitbart, Newsmax and Zero Hedge, were more than twice as likely to be vaccine hesitant.

“Our work reveals a strong association between people’s specific media habits and their attitudes towards vaccination,” said author Lauren Gardner, director of Johns Hopkins’ Center for Systems Science and Engineering and an expert in using data and modeling to better understand disease risk. “Our findings suggest that when everyone is already engaging online, where and how they choose to do so matters.”

The study is newly published in the journal Vaccine.

In 2025, more than 2,000 measles cases across 43 states were reported in the United States, the most cases since the highly infectious disease was declared eradicated in 2000. Almost all the cases occurred in unvaccinated people.

Measles cases continue to rise this year.

The outbreak follows a steady drop in childhood vaccination rates, including the MMR vaccine, across the country since the COVID-19 pandemic. Coverage among school children hovers at 93%—below the 95% herd immunity threshold needed to predict or limit the spread of measles.

Previous research has demonstrated that adults who rely on less authoritative health information sources for vaccine information, such as internet news and social media, were more hesitant about vaccinating their own children. But less was known about how people’s general news habits might tie into their vaccination beliefs.

Gardner’s team surveyed 2,970 adults last August. While most Americans, 83%, reported the MMR vaccine benefits outweighed the risks, roughly 1 in 6 respondents reporting feeling hesitant about the vaccine.

Hesitant adults were significantly younger, with 62% under age 44, and more likely to be parents. They were more likely to be racial minorities, lower-income, and less educated. They expressed more conservative political beliefs and were more likely to identify with the Republican party, 39%, or as an Independent, 33%. Hesitant adults were also more likely to identify with the Make America Healthy Again movement, or MAHA, 43%, than non-hesitant adults, 27%.

Most participants, 87%, reported following the news, with no significant differences between hesitant and non-hesitant adults. Almost everyone said they were online at least daily and almost everyone engaged with a variety of news sources.

The greatest difference between the news and information habits of vaccine hesitant and non-hesitant participants was what researchers called the “selective media engagement” of non-hesitant individuals.

While almost everyone surveyed said they were online at least daily and almost everyone consumed content across multiple mediums, outlets and platforms, non-hesitant adults were less likely to engage with right-leaning “new media” channels, and significantly less likely to obtain information from non-authoritative sources such as alternative health providers, online health influencers, alternative health newsletters.

The findings suggest that reliance on physicians for health information emerged as a strong protective effect against vaccine hesitancy and that to improve vaccination rates, health communicators must address how and where Americans find information about vaccines.

“With public health becoming increasingly polarized, it’s critical to understand people’s attitudes about vaccines, and this work suggest people’s media preferences play an outsized role in influencing those attitudes.” said co-first author Amelia Jamison, an assistant research scientist at Johns Hopkins, who studies health communication.