Humoral Vaccine Responses Following Chimeric Antigen Receptor T-cell Therapy for Hematological Malignancies

This single-center, retrospective study analyzed vaccine responses in patients who received post-Chimeric Antigen Receptor (CAR) T-cell therapy vaccination between 2018 and 2024. Vaccinations were administered according to EBMT/CIBMTR recommendations and pathogen-specific IgG responses to 12 vaccine-preventable infections were assessed. Seroprotection was defined by established cut-offs or a significant fold increase in titers. A total of 73 patients that had not received intravenous immunoglobulins within the eight weeks prior to pre- or post titer were included. The median time to vaccination initiation was 13 months (range 6–66) post-CAR T. Pre and post-vaccination titers were available for 49 patients. Pre-vaccination seroprotection was high (> 85