Impact of CD19 CAR T‐Cell Therapy on Pathogen‐Specific Antibody Titers in Lymphoma Patients

MeV, MuV, RuV, VZV, and tetanus toxoid IgG remained stable following CD19 CAR T-cell therapy, while pneumococcal and Hib IgG titers showed marginal quantitative declines, without any fourfold reductions. Overall, humoral immunity at Day 100 following CD19 CAR T-cell therapy remained largely preserved. These seroprevalence findings suggest that routine revaccination may not be required in our patient cohort and highlight the importance of patient monitoring to inform revaccination decisions.