Anthony Mato, MD, MSCE, Memorial Sloan Kettering Cancer Center, New York, NY, discusses antibody deficiency and infectious complications in patients with chronic lymphocytic leukemia (CLL), in particular talking on immunoglobulin replacement therapy as a potential intervention for infections in patients with CLL, as well as commenting on COVID-19 vaccination. This interview took place at the virtual European Hematology Association (EHA) Congress 2021.