ABSTRACT
Coronavirus disease 2019 (COVID-19) is sweeping the world with strong infectivity and high mortality, but by now, we still lack specific treatment. The leading cause of death from COVID-19 is failure to eliminate those viruses effectively. Cellular immunity plays a crucial role in the body's elimination of coronavirus, so it is necessary to study cellular immunity on the basis of plasma therapy. Blood components of convalescents without erythrocytes contains all the components of cellular immunity and humoral immunity in blood. Current studies had shown that all neutrophils, specific antibodies, interferons, platelets, specific effect cells and memory cells, play irreplaceable roles in the immune process of eradicating coronavirus. This article summarizes the infusion safety, therapeutic mechanism of all above components, and their effects on immunologic derangement and excessive inflammatory response, in order to provide an alternative reference for the treatment of COVID-19.