Heterogeneous Vulnerability and Vaccination Behavior: Evidence from Experimental Games

Abstract Understanding the impact of population heterogeneity on the spread of vaccine-preventable diseases is crucial for containment and control. Here, we develop an experimental game model to examine how risks from disease and vaccination shape vaccination decisions in a population with heterogeneous vulnerability. Our results show that participants vaccinate strategically in line with Nash equilibrium. Specifically, vaccination rates were higher among more vulnerable individuals than among those less vulnerable. Additionally, we observed minimax behavior in a subset of individuals who consistently chose the secure option (vaccination) regardless of others’ actions. These findings underscore the epidemiological interdependence of vaccination decisions and the need for public health approaches that recognize the different risks and costs faced by vulnerable groups.