P1629: ADMINISTRATION OF CONVALESCENT PLASMA FOR THE TREATMENT OF SEVERE COVID-19: RESULTS OF A MULTICENTER PHASE II TRIAL. (23rd June 2022) - Thomopoulos, T.; Bouchla, A.; Antoniadou, A.; Terpos, E.; Politou, M.; Stamoulis, K.; Koromboki, E.; Papageorgiou, S.; Kotanidou, A.; Kalomenidis, I.; Jahaj, E.; Grigoropoulou, S.; et al.