CHAPTER 9: Infection and Pathogenesis of SARS-CoV-2: an Immunological Perspective

The coronavirus disease 2019 (COVID-19) pandemic which started in December 2019 has turned into a disaster and spread across the globe. COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is suspected to be first transmitted through infected bats and pangolins. The virus has evolved numerous ways to defend itself from the immune system, such as inhibiting interferon production, and escaping pattern recognition receptor sensing. The fight between SARS-CoV-2 and the immune system determines the severity and outcome of COVID-19. During this fight, there are several symptoms that might help in predicting COVID-19 severity, one of the most important being the huge production of pro-inflammatory cytokines that lead to the cytokine storm. Other markers include lymphopenia, increased antibody production, and impaired dendritic cells. However, the result of the fight is also influenced by several factors such as age, gender, genetic variation, blood group, and comorbidities. These factors, as well as symptoms, might be used to predict the severity of COVID-19 and suggest medications and precautions accordingly. Because it has tremendously affected the world, there is an urgent need to develop therapeutics and vaccines that can be used to eradicate the virus permanently.