"A single viral video can undo months of health education": social media, trust, and vaccine hesitancy in wartime Ukraine.

This study examines vaccine hesitancy in wartime Ukraine, where institutional mistrust, displacement, and emotional trauma reshape parental decision-making. Drawing on in-depth interviews with mothers and pediatric professionals, we explore how caregivers navigate immunization choices amid disrupted health systems, contested information environments, and weakened trust in state and international actors. We frame hesitancy not as a static or irrational stance but as a dynamic process shaped by context, history, and emotion. Findings reveal that hesitancy stems from intersecting structural and interpersonal factors, including the erosion of institutional credibility, fear-based digital content, and generational memories of coercive medicine. Mothers often rely on social networks and peer narratives to fill gaps left by healthcare services, while providers struggle to communicate effectively under wartime pressures. Vaccine decision-making in this context is deeply relational, moral, and affective, extending beyond biomedical considerations. Addressing hesitancy in conflict-affected settings requires public health strategies that move beyond access and education, prioritizing empathetic communication, rebuilding trust, and acknowledging the emotional and symbolic dimensions of vaccination during crisis.