Novel protocol for selection of SARS-CoV2 convalenscent plasma donors

Introduction. SARS-CoV2 2019 infection represent global problem. At this moment there is no vaccine or efficient treatment of infected patients. Treatment with blood plasma rich with anti SARS-CoV2 specific antibodies represents rare safe and effective treatment of Covid19 patients. Patients and Material. A total number of 950 patients were analyzed in this study, whose samples were collected in time interval from 01.05. till 15.08.2020. Patients were enrolled in study from Covid-19 hospitals, out-clinics and as family members of SARS-CoV2 infected patients. Original ELISA tests were developed to measure the concentration of anti-S1S2 Spike and anti-Nucleoprotein (IgG, IgA, IgM) SARS-CoV2 antibodies. Blood convalescent plasma was selectively collected from recovered patients according to specific antibodies concentration. Results. The highest concentrations of anti-S1S2 Spike or anti-Nucleoprotein specific IgG antibodies were detected in patients with the moderate/heavy clinical form of infection as well as in group of family members of SARS-CoV2 infected patients. Extremely high concentration of anti S1S2 Spike IgG and anti-Nucleoprotein IgG was demonstrated in 3% and 6% (respectively) of patients recovered from severe Covid19. From our hospitalized patients 63% and 51% had modest antibody levels (anti S1S2 Spike and anti-Nucleoprotein, respectively). After 60 days, in our selected donors’ concentration of anti S1S2 Spike IgG antibodies increased in 67%, paralleled with increase of anti-Nucleoprotein IgG antibodies in 58% of donors. Conclusion. Originally developed ELISA tests enable novel protocol for selection of convalescent blood plasma donor.