Evaluating the spread of Omicron COVID-19 variant in Spain

This work analyzes the propagation of Omicron, a high transmissible COVID-19 variant, across Spain by means of EpiGraph. EpiGraph is an agent-based parallel simulator that reproduces the COVID-19 propagation over wide areas. In this work we consider a population of 19,574,086 individuals related to the 63 most populated cities of Spain for the time interval comprised between May 15th of 2021 and March 6th of 2022. The main variants existing at the start of the simulation were the Alpha and Delta, with a a 4% and 96% prevalence of the existing infections, respectively. Then, during the second mid of November of 2021 the Delta variant appears in Spain. Given to the higher transmission of this new variant-about 2 times larger than Delta-, it quickly spreads through all the cities and becomes the dominant strain of the country. In this work we analyze the propagation of this variant under multiple conditions. First, we define a baseline scenario, that reproduces the existing conditions of the COVID-19 propagation in Spain for this period. Then, we consider alternative scenarios, in which different locations of the initial spread of Omicron variant are considered. Finally, for each one of these scenarios, we evaluate different transportation intensities-i.e. movement of individuals between the cities-. The main conclusion of this work is that, independently of the initial location of the Omicron variant, and the existing transportation conditions, the Omicron variant spreads though all the country in a short time interval.