Researchers develop new tool to simulate the impact of SARS-CoV-2 strains and vaccines The MOMAT research group from Universidad Complutense de Madrid has worked with Universidad de Almería, to develop a mathematical model that simulates the impact of SARS-CoV-2 strains and vaccines together, combined with many other biological and social processes in the propagation of COVID-19. The tool can be downloaded without restriction and free of charge and applied to any territory. It forms part of the family of θ-SIR models, which were initially developed by the MOMAT research group itself before the arrival of new variants and the development of vaccines.