The Virology, Immunity and Vaccine Development of SARS-CoV-2

Since the last months of 2019, the COVID-19 pandemic caused by SARS-CoV-2, a brand new coronavirus, catches our attention on our agenda as it harms economic and socio-cultural structures almost all around the world. For the elimination of SARS-CoV-2, there has to be an effective and sufficient immune response that includes innate and adaptive immunity against the virus. Also, this immunity should help us to prevent and control the infection. However, there are some complications about our body’s response to this virus: Hyperactivation of the immune response can cause tissue damage and organ failures. On the other hand, immunodeficiency is one of the major obstacles to the elimination of the virus. Type I IFN response is essential for COVID-19 disease. Some of the SARS-CoV-2 infection pathogenesis is caused by delay, deficiency, or inhibition of IFN release. The infection can be limited if type I IFN is secreted early and adequately. The overproduction of pro-inflammatory cytokines (such as IL-1, IL-6, and TNFα), neutrophilia, and lymphopenia is associated with COVID-19 disease severity and mortality in patients. Our current understanding of SARS-CoV-2 immunity is still limited. Further clarification of the immunopathogenesis of COVID-19 disease will guide us in both diagnosis and treatment. It will also shed light on new drugs and vaccine studies. Therefore, extensive researches on the host immune response against SARS-CoV-2 are still necessary.