The onset of the COVID-19 pandemic highlighted the need for education in disease transmission and prevention. In response, the University of California 4-H Youth Development Program implemented a virtual epidemiology project, based on resources developed by the Centers for Disease Control and Prevention (CDC) and collaborating agencies. The teenage participants were actively engaged in group lessons focused on epidemiology, immunology, vaccination, zoology, prevention strategies, related careers, and health communication. Surveys administered before and after the program showed an increase in knowledge about vaccinations and disease transmission and improved attitudes toward, and intentions to adopt, practices that reduce the spread of disease. They also showed increased self-efficacy and positive health behaviors (hand washing and mask use, and the intention to share what they learned in their communities). These findings contribute to the development of public health and epidemiological education programs for adolescents and programming that elevates youth as messengers of health information.