Efficacy and safety of transfusing plasma from COVID-19 survivors to COVID-19 victims with severe illness. A double-blinded controlled preliminary study

Background
COVID-19 is highly contagious, potentially deadly current pandemic with no evidence-based cure or vaccines. The efficacy and safety of transfusion plasma of recovered patients were tested to treat patients with severe infection.
Method
In this preliminary, controlled study, 30 patients were allocated to one of two groups: Standard therapy group (control, n = 15) and recovered COVID-19 plasma group (RCP, n = 15). Control group, received standard therapy alone, while patients allocated to RCP group, were given a single dose,250 ml, of plasma of recovered COVID-19 individuals, plus standard COVID-19 therapy. Neutralizing antibodies and severe COVID-19 serum biomarkers e.g. C-reactive protein, ferritin and d-dimer were measured in all patients before and after transfusion. Our primary outcome was reduction of two or more of a four-category illness-severity scale over 5 days study period: Respiratory frequency ≥24/min, blood oxygen saturation ≤ 93% on room air, partial pressure of arterial oxygen to fraction of inspired oxygen ratio < 300 mmHg, pulmonary infiltrates >50% of both lungs.
Results
Plasma of recovered COVID-19 resulted in improvement of laboratory and radiological findings. In RCP group, there was statistically significant improvement of clinical parameters, as well as serum ferritin, D-dimer, c-reactive protein, and the size of lung lesion compared to control group (P ≤ 0.05). COVID-19 neutralizing antibodies appeared in serum of RCV patients, but failed to show in the control group patients during 5 days study period.
Conclusion
Plasma of recovered COVID-19 individuals is safe and effective therapeutic modality that significantly accelerated clinical improvement in patients with severe COVID-19 infection.