Public debates about vaccination often turn on evidence and persuasion, yet beneath these lie deeper differences in how people prefer to make health decisions. This lecture examines how such decision-making preferences—whether one leans toward autonomy or authority, caution or intervention—shape vaccination attitudes and behaviours. Drawing on empirical evidence from large-scale surveys, I show how preferences complement more familiar factors such as risk perception and social norms. Recognizing these patterns helps explain why communication strategies resonate with some audiences but not others. I then turn to the broader implications: when individual preferences aggregate, they influence vaccine uptake and, in turn, the dynamics of epidemics. Linking psychology and epidemiology, the lecture offers a richer view of agency in public health.