Public health is often most successful when you don’t notice it—when clean water prevents outbreaks, vaccines stop disease before it spreads, and everyday protections quietly save lives. In this UC Berkeley Grad Lecture, epidemiologist and science communicator Dr. Katelyn Jetelina explores why that long-standing “invisible” nature of public health has become a problem. When people can’t see how public health affects their daily lives—or don’t trust the messengers behind it—support erodes, misinformation fills the gaps, and systems meant to protect communities are put at risk.

Jetelina traces this challenge through history, noting that fear and skepticism have always followed public health efforts. What’s changed is today’s information landscape. Trust in institutions and traditional media has weakened, while social platforms allow false or misleading claims to spread faster than evidence-based explanations. Public health now operates in what she describes as a five-alarm fire—where communication failures can directly influence behavior, policy, and health outcomes during times of crisis.

At the heart of the problem, Jetelina argues, is a “last-mile” gap between research and real-world impact. Producing data isn’t enough if it remains locked behind paywalls or presented in ways that are hard to understand or act on. Making public health visible means translating science into clear, relatable information—using plain language, thoughtful visuals, and stories that connect data to lived experience. When people understand the value of public health, they’re far more likely to trust it and engage with it.

She illustrates this with practical examples, including public dashboards that overwhelm users with charts but offer little guidance. Jetelina highlights the importance of designing tools with specific audiences in mind—resources that not only show risk, but also explain what to do next. Ultimately, she emphasizes that trust can’t be built during a crisis; it must be earned beforehand through consistent, two-way communication. By listening to communities and meeting people where they are, public health can become visible not just in emergencies, but as an everyday force for collective well-being.

Watch Public Health: How to Make the Invisible Visible with Katelyn Jetelina.