SARS-COV-2 Virus; Immune Responses and The Immunopathogenesis

Abstract Background and Objectives Clinical features of SARS-COV-2 virus include fever, headache, cough, sore throat, and shortness of breath, and in severe forms it leads to disseminated intravascular coagulation, septic shock, and ultimately death. Excessive secretion of proinflammatory cytokines such as TNF-α, IL-6, and IL-1 leads to cytokine storms in this disease. The emergence of new variants of the SARS-CoV-2 virus, which occurs following a high mutation of the virus, increases its ability to escape the immune system and improve its transmission power. This process, in turn, can lead to ineffective vaccines against the virus. Due to the effect of the emerging viruses on the safety of blood and its products, in the first part of this article, the topic of virology, immune responses, and immunopathogenesis of this virus were discussed. The second part will discuss the viral-related issues of blood safety and its products. Materials and Methods In this review, keywords were searched in Science Direct, PubMed, Scopus databases and the sites of Nature, Science, Elsevier, Cell, BMJ, and Lancet journals, and finally 148 articles were used. Results In this article, in addition to a brief review of SARS-CoV-2 and its new variants from a virological point of view, its immunology and immunopathogenesis are also discussed. Conclusions  Due to the widespread SARS-CoV-2 virus and its unprecedented nature in causing the disease, it is essential to address it. However, based on the genomic nature of the virus, the high probability of various mutations and the emergence of new variants, accurate and comprehensive information on the virus abilities to escape the immune system and its pathogenic mechanisms is not yet available. There are many contradictions in these topics. However, the latest available and reliable scientific materials at the time of the preparation of this article have been tried to be reviewed.