Social networks and vaccination: a perspective on the essential role of social networks to improve vaccination outcomes in public health.

Vaccines protect against life-threatening diseases and save millions of lives each year in people of all ages, but vaccination rates remain suboptimal and inequitable. Social networks, in which individuals are linked, offer capacity to transmit infectious diseases and protection against them by the diffusion of vaccination behavior. However, social networks are underutilized in public health strategies. This perspective paper advances a network-informed framework that reconceptualizes vaccination behavior as socially embedded. We integrate behavioral drivers with network processes, such as social selection and social influence, and outline how these processes generate network structures that shape vaccination outcomes. We further translate these insights into actionable strategies, including network diagnostics, targeted approaches to alter network structure, and approaches that leverage diffusion. Incorporating social network thinking can strengthen both the effectiveness and equity of vaccination programs.