Before revision:  The dynamics of this modified SIR system is analysed and the exact computation of some epidemiologically relevant quantities is performed , since both models have been recently used in order to describe the essentials of the dynamics of the COVID-19 pandemic .
After revision:  The dynamics of this modified SIR system is analyzed and the exact computation of some epidemiologically relevant quantities is performed , since both models have been recently used in order to describe the essentials of the dynamics of the COVID-19 pandemic .