Preparing for the possibility of a global pandemic presents a transnational organisational challenge: to assemble and coordinate knowledge over institutionally diverse countries with high fidelity. The COVID-19 pandemic has laid these problems bare. This article examines the construction of the three main cross-national indicators of pandemic preparedness: a database with self-reported data by governments, external evaluations organised by the WHO and a global ranking known as the Global Health Security Index. Each of these presents a different model of collecting evidence and organising knowledge: the collation of self-reports by national authorities; the coordination of evaluation by an epistemic community authorised by an intergovernmental organisation and on the basis of a strict template; and the cobbling together of different sources into a common indicator by a transnational multi-stakeholder initiative. We posit that these models represent different ways of creating knowledge to inform policy choices, and each has different forms of potential bias. In turn, this shapes how policymakers understand what is ‘best practice’ and appropriate policy in pandemic preparedness.