The path toward regaining control of measles may start with who tells the story, says a McMaster researcher who examined the 2025 measles outbreak in North America through a social lens. Canada lost its measles elimination status in late 2025, and the United States is now at risk of losing its own, as cases there surge.
Rachel Zhou, a professor in the Department of Health, Aging and Society, studied thousands of Reddit conversations to understand how people made sense of the measles’ resurgence in 2025. The posts reveal more than opinions about vaccines, she says. They show how people remember – and forget – disease, how politics shapes health decisions and how people’s stories can open doors when facts alone aren’t enough.
“Measles is a disease many considered from another era. When it resurfaced widely in North America in 2025, it raised an interesting question: How can something so well understood and preventable come back in high-income places like the U.S. and Canada? That puzzle drew me in,” explains Zhou.
Her analysis shows that when news of outbreaks hit Reddit, discussions quickly turned not just to science, but to memory and intergenerational stories, which often softened political divides and created rare moments of shared understanding.
“Vaccines work — but only when people accept them. Right now, trust in institutions is low. In this environment, who delivers the message may matter more than the message itself.”
The hopeful news, she says, is that trusted messengers already exist. Grandparents, neighbours and friends carry lived memories of what measles once meant. Those personal stories may be one of the most powerful tools we have to foster trust and protect each other.
What drew you to study the 2025 measles outbreak from a social perspective?
I’ve studied other contagious diseases like HIV/AIDS, SARS, COVID-19, so when measles resurfaced in North America, it immediately caught my attention. It felt both novel and urgent.
This outbreak also intersects with several of my research interests. I study global health, mobility and time — how diseases travel across borders, but also across generations. Measles brings all of this together: it’s an old disease that’s suddenly appearing again. People who lived through earlier outbreaks are still alive today and this is all unfolding in a politically-divided environment that shapes how people respond to health guidance. Those overlapping dimensions made me feel that I might have something meaningful to contribute.
Why use Reddit for this study, and what did you learn from those online conversations?
Reddit is an interesting source of data because it’s different from other social platforms. Subreddits often function like longstanding communities. Even though users are anonymous, they build relationships and return to the same topics over time. When something urgent happens, like a measles outbreak or a related child’s death, people post news links immediately and others respond with their own questions, memories or concerns.
When I analyzed the measles discussions, one thing that really surprised me was how many people shared intergenerational stories. We often assume Reddit is dominated by younger users, but many people talked about their own childhood experiences with measles or vaccination or stories from parents, grandparents, aunts and uncles. Some described relatives who nearly died decades ago. These are people a researcher could never easily “recruit,” yet they volunteered these memories themselves.
I also paid close attention to time-related language. People called measles an “old-fashioned disease” or something that had “come back” from the past. That kind of framing helped me analyze how the public understands a disease that feels both historical and current.
What did these conversations reveal about vaccine hesitancy and polarization?
Measles is interesting because it requires a very high vaccination rate to achieve heard immunity – around 95 per cent. That means society really does have to work together, even when political beliefs differ. From a social science perspective, that raises the question: How do we build that level of solidarity in an increasingly divided society?
One thing the Reddit discussions showed is how easily labels like ‘antivax’ can shut down dialogue. People use that term quickly, but it can push others away and make meaningful conversation impossible. Many users discussed distrust of institutions, which is something that intensified during COVID19. That distrust won’t disappear overnight.
The hopeful part is that storytelling seemed to cut through some of that polarization. When people shared personal or family experiences with measles, it opened emotional space for others to listen and made discussions less confrontational. Instead of arguing over politics, they were remembering what measles actually felt like for previous generations. That emotional connection matters.
Based on your findings, what might help public health teams communicate more effectively?
I think we need creativity. In this moment of institutional skepticism, traditional public health messaging like people in lab coats telling you what to do may not always work. Facts are essential, of course, but who delivers those facts can make a difference.
My study suggests that trusted messengers are already all around us: neighbours, grandparents, community members who carry lived memories of measles. Some people may not trust institutions right now, but they may trust the people they’ve known for decades. When someone says their aunt nearly died from measles before the vaccine, that story lands differently than a statistic.
I don’t think storytelling replaces scientific evidence, but it can be a powerful complement. It’s a way to reach people who are hesitant about vaccines or overwhelmed by misinformation. We may not be able to solve polarization quickly, but we can find ways to work within it, using forms of trust that already exist. That gives me hope.