  The outbreak and propagation of COVID-19 have posed a considerable challenge
to modern society. In particular, the different restrictive actions taken by
governments to prevent the spread of the virus have changed the way humans
interact and conceive interaction. Due to geographical, behavioral, or economic
factors, different sub-groups among a population are more (or less) likely to
interact, and thus to spread/acquire the virus. In this work, we present a
general multi-group SEIRA model for representing the spread of COVID-19 among a
heterogeneous population and test it in a numerical case of study. By
highlighting its applicability and the ease with which its general formulation
can be adapted to particular studies, we expect our model to lead us to a
better understanding of the evolution of this pandemic and to better
public-health policies to control it.
