Temporal Dynamics of Vaccination Decision-Making: How Trust and Risk Perception Evolved During COVID-19 in Germany

The COVID-19 pandemic created unprecedented conditions for examining how vaccination willingness evolves during prolonged health crises. This longitudinal mixed-methods study examines temporal dynamics in COVID-19 vaccination willingness across three phases of Germany’s vaccination campaign (N = 1063 survey respondents; n = 40 interview participants). Using mixed-effects models and thematic analysis, we tested whether institutional trust and personal risk perception predict vaccination willingness and how their relative importance changes over time. Results reveal that trust in scientific institutions emerges as the strongest predictor, outperforming political trust and becoming more influential over time, while risk perceptions become less predictive with time. Qualitative analysis identified a multitude of different argumentative themes for and against COVID-19 vaccination (as well as conditional acceptance), with 30% of participants expressing both. The themes complement the quantitative analysis by demonstrating a shift from analytical, risk-focused decision-making to heuristic, trust-based processing as vaccination campaigns progress, with important implications for adaptive public health communication strategies.