Immune Response for SARS CoV-2

COVID 19 is the third one among zoonotic coronavirus, first and second being SARS-CoV and MERS-CoV, respectively. WHO has declared the coronavirus disease 2019 a pandemic on March 11th, 2020. The last pandemic was reported in the year 2009, which was H1N1 flu. The early eradication of COVID 19 seems impossible as it has never been identified in humans previously. There is a need to understand the basic immunology of this disease, to develop vaccines and medicines to save the global population from this novel coronavirus. The immune system protects against pathogens by producing antibodies to kill the pathogens that enter our bodies. Lymphocytes play a major role because they recognize the virus and produce antibodies against them, but people infected with COVID 19 showed a decline in the number of lymphocytes. Lymphocytes include T-cells, B-cells, Natural killer cells. About 15% of COVID 19 patients develop pneumonia, and about 5% end up in multiple organ failure where the immune response is critically impaired. The clinical conditions associated with Covid 19 include cytokine storm and acute respiratory distress syndrome (ARDS). In addition, changes in Acute Phase Reactants proteins (APR) have also been reported. This chapter aims to improve the understanding of the immune response and immunopathological changes that have been witnessed in patients suffering from this disease.