Coronavirus-19 disease (COVID-19) first described in Wuhan, China at the end of 2019. It spread rapidly all over the world and claimed the lives of over 300,000 people. There is no known effective vaccine and treatment yet. It is impossible to develop vaccines and specific treatment without understanding the pathogenesis of the disease. Experience from severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) outbreaks may help to elucidate the pathogenesis of COVID-19. Nevertheless, many issues remained obscure regarding the pathogenesis of SARS-CoV-2. Exaggerated immune response leads to respiratory failure and even complications which may culminate in death. Cytokines storm, the complement system, endothelial damage, coagulation cascade, cellular and humoral immunity all play an important role in immune pathogenesis and inflammation. In this review, the relationship between the immune response/host characteristics of SARS-CoV-2 and the severity of the disease, antibody responses, and immune pathogenesis, possible causes of hypercoagulation will be discussed and it's aimed to provide perspective on the development of effective vaccines and specific treatment.