E-Mail Concerns over infecting others play a greater role in people's willingness to be vaccinated in sparsely populated areas than dense urban ones, according to newly published findings in the Proceedings of the National Academy of Sciences ( PNAS) of the United States. Researchers at the University of Illinois at Urbana-Champaign and the Annenberg Public Policy Center (APPC) of the University of Pennsylvania examined people's behavior getting a flu vaccine as well as their future intentions to be vaccinated against the flu and COVID-19. Given that they encounter more people and have a greater risk of transmitting disease, it might seem that people in urban environments would be more highly motivated to vaccinate because of "prosocial" concerns - to protect others. But that is not what the research found.