  Based on the classical SIR model, we derive a simple modification for the
dynamics of epidemics with a known incubation period of infection. The model is
described by a system of integro-differential equations. Parameters of our
model directly related to epidemiological data. We derive some analytical
results, as well as perform numerical simulations. We use the proposed model to
analyze COVID-19 epidemic data in Armenia. We propose a strategy: organize a
quarantine, and then conduct extensive testing of risk groups during the
quarantine, evaluating the percentage of the population among risk groups and
people with symptoms.
