A multi-phase, multi-method assessment of national COVID-19 vaccination performance with equity analysis

The COVID-19 pandemic, originating in Wuhan, China, rapidly escalated into a global crisis, straining public health systems and economies. This study proposes a data-driven framework to evaluate the response performance of 143 countries across three phases: pre-vaccination, vaccination, and post-vaccination. Countries are clustered using K-means clustering based on pandemic-related indicators, and indicator importance is derived using an objective weighting method that accounts for variability and interdependence. Three Multi-Criteria Decision-Making (MCDM) methods (MACONT, COCOSO, and EDAS) are then applied to rank countries within clusters. The framework integrates diverse measures, including healthcare capacity, economic resilience, and the Risk INFORM COVID-19 index, enabling a holistic evaluation. Results reveal notable differences in country performance over time, with early vaccination rollout and strict public health policies associated with more stable rankings. Key determinants include the strength of the healthcare system, economic adaptability, and equitable vaccine distribution. An equity analysis using the Gini coefficient highlights significant disparities in global vaccine access, emphasizing the urgency of coordinated policy action. Finally, by tracking country movements across clusters, the study provides insights into evolving national responses. It concludes with recommendations for improving global preparedness and building more resilient, equitable systems for future health emergencies.