When to Lift the Lockdown? Global COVID-19 Scenario Planning and Policy Effects using Compartmental Gaussian Processes
The coronavirus disease 2019 (COVID-19) outbreak has led government officials and policy makers to rely on mathematical compartmental models for estimating the potential magnitude of COVID-19 patient volume, particularly at the local peak of the epidemic, in order to make containment and resource planning decisions. Now that the pandemic is already past its peak in many of the hardest hit countries, policy makers are trying to figure out the best policies for gradually easing the lockdown to resume economic and social activity while protecting public health. In this paper, we develop a model for predicting the effects of government policies on COVID-19 fatalities – the developed model (1) is flexibly able to handle model miss-specification in a data-driven fashion, (2) is able to quantify the uncertainty in its forecasts, and (3) is able to capture the effect of interventions on these forecasts. Our model is Bayesian: we use a susceptible, exposed, infected and recovered states (SEIR) model as a prior belief on the pandemic curve, and then update the posterior belief based on observed data using a Gaussian process. We incorporate the effects of policies on the future course of the pandemic by calibrating the priors using global data from many countries.
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