Data-driven Optimized Control of the COVID-19 Epidemics

TL;DR

This paper develops a data-driven optimal control model for COVID-19 that balances epidemic suppression with economic impact, revealing that constant, stricter social distancing levels are often optimal and that vaccination effects can reduce the need for social distancing.

Contribution

It introduces a novel optimal control framework tailored to different US metropolitan areas, incorporating data, time-varying controls, and vaccination effects to inform social distancing policies.

Findings

Optimal control levels are often constant and stricter than current policies.

The duration of control application varies by area, being short, long, or intermediate.

Vaccination can allow for reduced social distancing measures during rollout.

Abstract

Optimizing the impact on the economy of control strategies aiming at containing the spread of COVID-19 is a critical challenge. We use daily new case counts of COVID-19 patients reported by local health administrations from different Metropolitan Statistical Areas (MSAs) within the US to parametrize a model that well describes the propagation of the disease in each area. We then introduce a time-varying control input that represents the level of social distancing imposed on the population of a given area and solve an optimal control problem with the goal of minimizing the impact of social distancing on the economy in the presence of relevant constraints, such as a desired level of suppression for the epidemics at a terminal time. We find that with the exception of the initial time and of the final time, the optimal control input is well approximated by a constant, specific to each area, which contrasts with the implemented system of reopening `in phases'. For all the areas considered, this optimal level corresponds to stricter social distancing than the level estimated from data. Proper selection of the time period for application of the control action optimally is important: depending on the particular MSA this period should be either short or long or intermediate. We also consider the case that the transmissibility increases in time (due e.g. to increasingly colder weather), for which we find that the optimal control solution yields progressively stricter measures of social distancing. {We finally compute the optimal control solution for a model modified to incorporate the effects of vaccinations on the population and we see that depending on a number of factors, social distancing measures could be optimally reduced during the period over which vaccines are administered to the population.