Novel Coronavirus, COVID-19 discovered in December, 2019 in Wuhan, China started a world-wide epidemic. It is not clear till now what is the pathogenesis of this virus infection in human or the exact strategies of host immune response in combating this novel threat to human beings. However, morbidity and mortality of COVID-19 infections vary widely from asymptomatic, mild to deadly critical. Strangely, children were found to be protected from severe or deadly critical infections, while elderly and immunocompromised adults are most affected badly by this virus. It is necessary to disclose the possible viral and host interactions that lead to such variable morbid effects among patients of COVID-19 infections.