COVID-19 is not the first severe respiratory disease outbreak caused by the coronavirus. Just in the past two decades, coronaviruses have caused three epidemic diseases, namely, COVID-19, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). At present, the cases of COVID-19 have been found in many countries around the world. Here, we provide an outline of the pathophysiology of SARS-CoV-2 infection. Also, we describe the interaction of SARS-CoV-2 with the cell mediated immune system and the subsequent contribution of dysfunctional immune responses to disease progression. Understanding the immunological response to the SARS-CoV-2 viral infection will help us to develop successful treatments and vaccines, identify vulnerable groups and help inform public health measures to control the coronavirus outbreak.