What We Know (and Don’t Know) About Global Vaccine Manufacturing Capacity

Global vaccine manufacturing capacity remains poorly defined, inconsistently measured, and insufficiently understood—limitations that undermined the COVID-19 response and, without progress, will constrain responses to future pandemics too. This paper synthesises evidence from 17 major studies and five stakeholder consultations to map how capacity is currently assessed, what these approaches capture, and where critical blind spots persist. We find that existing assessments rely on heterogeneous definitions, static surveys, and proprietary or incomplete datasets, offering limited visibility into platform-specific capabilities, input bottlenecks, surge potential, and real-world timelines for scaling production. COVID-19 exposed these weaknesses: uncertain capacity estimates, unanticipated raw-material constraints, and limited insight into platform flexibility hindered coordinated global response. Our review highlights major methodological gaps—including a lack of standardised metrics, limited predictive modelling, and uneven transparency—that impede comparability and decision-making. We propose an integrated framework emphasising three priorities: (1) establishing shared, platform-specific metrics for capacity and surge readiness; (2) building a brokered, confidentiality-protected data system for aggregating global manufacturing information; and (3) shifting from static capacity counts toward scenario-based analysis that reflects supply-chain fragilities, regulatory processes, and workforce readiness. Strengthening these foundations is essential to move from fragmented visibility to actionable, resilient global manufacturing preparedness.