Immunogenicity of the 13-Valent Pneumococcal Conjugated Vaccine Followed by the 23-Valent Polysaccharide Vaccine in Chronic Lymphocytic Leukemia

Patients with Chronic Lymphocytic Leukemia (CLL) have a 29- to 36-fold increased risk of invasive pneumococcal disease (IPD) compared healthy adults. Therefore, most guidelines recommend vaccination the 13-valent conjugated vaccine (PCV13) followed 2 months later by 23-valent polysaccharide (PPSV23). Because both CLL as well immunosuppressive treatment been identified major determinants immunogenicity, we aimed assess schedule in untreated and treated patients. We quantified IgG concentrations against five serotypes shared across vaccines, four unique PPSV23, before eight weeks after vaccination. In this retrospective cohort study, included 143 patients, either (n = 38) or naive 105). While antibody significantly vaccination, overall serologic response was low (10.5%), defined ≥4-fold increase ≥70% measured serotypes, influenced status prior lymphocyte number. The protection rate, an concentration ≥1.3 µg/mL for 13% 3% Future research should focus on regimens higher immunogenic potential, such multi-dose schedules higher-valent T cell dependent vaccines.