Effectiveness and immunogenicity of pneumococcal vaccination in splenectomized and functionally asplenic patients

The aim of the present study was to evaluate the effectiveness and immunogenicity of pneumococcal vaccination in 145 splenectomized and 2 functionally asplenic patients receiving the 23-valent pneumococcal polysaccharide vaccine and/or the 7-valent pneumococcal conjugate vaccine (PCV7) during the period 1996-2009. Progression of underlying malignant disease was the main cause of death in 68% of the 53 deceased patients, followed by septic shock in 13.2%. Twelve of 94 living patients developed post-vaccine complications: pneumonia in 9 patients, otitis media in 2, pneumococcal sepsis in 4. Compared with a non-splenectomized non-vaccinated control group (n = 34), splenectomized patients vaccinated in the previous five years (n = 15) had significantly higher GMCs (P < 0.05) against serotypes 4, 6B, 9V, 14, 18C, 19F and 23F. Our data demonstrated strong serological responses in splenectomized patients within the first 5 years after pneumococcal vaccination by PCV7. Nevertheless, post-vaccine pneumococcal sepsis was still diagnosed in 3.3% of splenectomized survivors.