P1513: REDUCTION OF THE PROPHYLACTIC EFFECT OF TIXAGEVIMAB-CILGAVIMAB IN THE OMICRON ERA IN PATIENTS WITH HEMATOLOGICAL MALIGNANCIES AND WITHOUT ANTIBODY RESPONSE FOLLOWING SARS-COV-2 VACCINATION. - Chiara Callegari; Martina Mutti; Alessandra Soravia; Pietro Lauzzana; Davide Lazzarotto; Maddalena Peghin; Stefano Cordella; Renato Fanin; Anna Candoni (HemaSphere, 2023)