Before revision:  We take on this task by converting the symptom onset time distribution, which we calibrated , into the percentage of the latent, pre-symptomatic and symptomatic groups through a novel mathematical procedure .
After revision:  We take on this task by converting the symptom onset . The model is calibrated against incubation period and serial interval statistics during early stages of the pandemic. Mathematical treatment of the model yields explicit expressions for the size of latent and pre-symptomatic subpopulations during the exponential growth phase .