  The present work shows that it is possible to analytically solve a general
model to explain the transmission dynamics of SARS-CoV-2. First, the
within-host model is described, and later a between-host model, where the
coupling between them is the viral load of SARS-CoV-2. The within-host model
describes the equations involved in the life cycle of SARS-CoV-2, and also the
immune response; while that the between-Host model analyzes the dynamics of
virus spread from the original source of contagion associated with bats,
subsequently transmitted to a host, and then reaching the reservoir (Huanan
Seafood Wholesale Market in Wuhan ), until finally infecting the human
population.
