Pneumococcal infections remain frequent and potentially fatal. To prevent them, two anti-pneumococcal vaccines exist: a 13-valent conjugate vaccine (Prevenar®) and a 23-valent polysaccharide vaccine (Pneumovax®). For their utilization, several studies approved a prime-boost strategy. It consist two administer Pneumovax® at least two months later than Prevenar®. Patients with diffuse large B-cell Lymphoma (DLBCL) have a higher-risk to develop a pneumococcal infection. The main reason is immunosuppression, induced by rituximab (B cell depletion), chemotherapy and lymphoma. Patients are treated by immunochemotherapy, combining rituximab (anti-CD20 monoclonal antibody) and conventional chemotherapy (CHOP). However, those patients have a low rate of vaccination (about 15%). Also, in the current literature, rare studies investigated prime-boost immunogenicity in this relevant population. The investigators will evaluate vaccinal response of 10 serotype-specific immunoglobulin G (1, 3, 4, 6B, 7F, 9V, 14, 18C, 19F, 23F) at different time of treatment.
The investigators search to compare efficiency of prime-boost anti-pneumococcal vaccination according to the time of prevenar administration (before or after immunochemotherapy) and to the dose of Prevenar® (single or double-dose).
