Before revision: In this work, different transmission modes of the SARS-CoV-2 virus  and their role in determining the evolution of the Covid-19 pandemic are analyzed  . Probability of infection caused by inhaling infectious droplets (initial, ejection diameters between 0.5-750\mu m) and probability of infection by the corresponding desiccated nuclei that mostly encapsulate the virions post droplet evaporation, are  calculated.
After revision: In this work, different transmission modes of the SARS-CoV-2 virus and their role in determining the evolution of the Covid-19 pandemic are analyzed . Probability of infection caused by inhaling infectious droplets (initial, ejection diameters between 0.5-750\mu m) and the corresponding desiccated nuclei that mostly encapsulate the virions post droplet evaporation, are calculated.