COVID-19 still represents a major issue for patients with lymphoid malignancies, especially those on therapy, because of immune suppression and suboptimal responses to vaccination. Davis et al report on their experience with double dose tixagevimab-cilgavimab preexposure prophylaxis in a cohort of 251 patients with chronic lymphocytic leukemia, B-cell lymphomas, multiple myeloma, or B-cell acute lymphoblastic leukemia, 63% of whom had received 3 doses of the SARS-CoV-2 vaccine. Breakthrough infections within 3 months occur despite passive immunization, affecting 11% in this series; however, hospitalization rates are low, and mortality was avoided, suggesting benefit from this strategy.