Why we need more data before the next pandemic

Attempts to control the current pandemic through public health interventions have been driven by predictions based on modelling, thus bringing epidemiological models to the forefront of policy and public interest. It is almost inevitable that there will be further pandemics and controlling, suppressing and ameliorating their effects will undoubtedly involve the use of models. However, the accuracy and usefulness of models are highly de?pendent on the data that are used to calibrate and validate them. In this article, we consider the data needed by the two main types of epidemiological modelling (compartmental and agent-based) and the adequacy of the currently available data sources. We conclude that at present the data for epidemiological modelling of pandemics is seriously deficient and we make suggestions about how it would need to be improved. Finally, we argue that it is important to initiate efforts to collect appropriate data for modelling now, rather than waiting for the next pandemic.