Before revision:  We construct and analyze here one first step: that of adapting a traditional SEIR epidemic model to the specific dynamic compartments and epidemic parameters of COVID-19 , as it spreads in an age-heterogeneous community.
After revision:  We construct and analyze here one first step: that of adapting a traditional SEIR epidemic model to the specific dynamic compartments and epidemic parameters of COVID 19 , as it spreads in an age-heterogeneous community.