In this combinatorial study let us try to simulate the four cases starting from viral spreading kinetics, Gaussian distribution of the infectious disease, mortality statistics like infection fatality ratio ( IFR ) with the distribution of age of the patient through sigmoid regression method approach and finally the most important modeling of remdesivir on the basis of Molecular bonding method ( LCAO)as well as vaccination as the traditional method. It is an alternative approach to susceptibility – infectivity – recovery ( SIR ) model .