Immune Reconstitution Monitoring and Pneumococcal Vaccination in Patients Treated With CAR-T Cells

This is a prospective interventional study designed to investigate the effect of Immune Reconstitution clinic visits and pneumococcal vaccination (PCV-21) on infection risk, anti-infective prophylaxis adherence, and vaccine response in patients receiving CAR-T therapy following lymphodepletion. Fifty subjects (20 receiving commercial CAR-T for CD19 or BCMA and 30 receiving investigational CAR-T) will be enrolled. Subjects will attend Immune Reconstitution Clinic Visits at 3, 6, 9, and 12 months after CAR-T cell infusion. Subjects will be asked to provide blood samples at pre-defined intervals during CAR-T visits which will be assessed for immune composition, vaccine titers, viral titers, and immunoglobulins. Samples will be primarily used for study purposes. Leftover blood will be stored for up to five years after the last study visit and may be used for future research. Vaccination against pneumococcal pneumonia will be offered at 6 months post-CAR-T infusion at the Immune Reconstitution Clinic Visit. Subjects will provide additional blood samples at 9- and 12 months post CAR-T infusion to assess anti-pneumococcal polysaccharide IgG antibodies to determine vaccine efficacy. Long-term follow-up will continue for up to 24 months post-CAR-T infusion via medical chart abstraction. This pilot study investigates immune reconstitution, infection risk, and vaccine response in patients receiving chimeric antigen receptor (CAR)-T cell therapy following lymphodepletion. Subjects will undergo lymphodepletion followed by CAR-T cell infusion will be included. The only additional treatment for subjects in this study is the PCV-21 pneumococcal vaccine. All CAR-T treatment procedures will adhere to the standard-of-care or the clinical trial protocol to which the subject is co-enrolled. Subjects will provide blood samples at predefined intervals during CAR-T visits. These samples will be assessed for various laboratory studies, including blood counts, immune cell composition, vi