Evaluation of Convalescent Plasma Therapy for COVID-19 Patients

INTERVENTION: Intervention 1: Intervention group: 20 patients are in the severe stage of the disease who receive plasma therapy with intravenous injection dose twice (200 ml per dose) and in addition to routine medical care. Intervention 2: Control group: 20 patients admitted to the severe stage of the disease who did not receive plasma therapy and receive only routine medical care. CONDITION: COVID‐19. ; COVID‐19 U07.1 PRIMARY OUTCOME: Percentage of patients discharged from the intensive care unit and hospital. Timepoint: Measurement of all standard clinical signs of the disease before the start of plasma therapy and after the start of each injection of plasma over specific intervals of up to one year (if surviving). Method of measurement: Patient file information. SECONDARY OUTCOME: Patient mortality rate. Timepoint: Recording the mortality rate for one year after starting plasma therapy. Method of measurement: Patient file information. INCLUSION CRITERIA: age between 20 to 60 years old