title: Pneumococcal conjugate vaccines overcome splenic dependency of antibody response to pneumococcal polysaccharides.
abstract: Protection against infections with Streptococcus pneumoniae depends on the presence of antibodies against capsular polysaccharides that facilitate phagocytosis. Asplenic patients are at increased risk for pneumococcal infections, since both phagocytosis and the initiation of the antibody response to polysaccharides take place in the spleen. Therefore, vaccination with pneumococcal polysaccharide vaccines is recommended prior to splenectomy, which, as in the case of trauma, is not always feasible. We show that in rats, vaccination with a pneumococcal conjugate vaccine can induce good antibody responses even after splenectomy, particularly after a second dose. The spleen remains necessary for a fast, primary response to (blood-borne) polysaccharides, even when they are presented in a conjugated form. Coadministration of a conjugate vaccine with additional nonconjugated polysaccharides of other serotypes did not improve the response to the nonconjugated polysaccharides. We conclude that pneumococcal conjugate vaccines can be of value in protecting asplenic or hyposplenic patients against pneumococcal infections.
authors.affiliation: Department of Pediatric Immunology, Wilhelmina Children's Hospital, University Medical Center, Utrecht, 3584 EA Utrecht, The Netherlands. M.Breukels@wkz.azu.nl
authors.forename: M A
authors.initials: MA
authors.lastname: Breukels
authors.forename: A
authors.initials: A
authors.lastname: Zandvoort
authors.forename: G P
authors.initials: GP
authors.lastname: van Den Dobbelsteen
authors.forename: A
authors.initials: A
authors.lastname: van Den Muijsenberg
authors.forename: M E
authors.initials: ME
authors.lastname: Lodewijk
authors.forename: M
authors.initials: M
authors.lastname: Beurret
authors.forename: P A
authors.initials: PA
authors.lastname: Klok
authors.forename: W
authors.initials: W
authors.lastname: Timens
authors.forename: G T
authors.initials: GT
authors.lastname: Rijkers
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D008297:Male; D011008:Pneumococcal Infections / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar; D012703:Serotyping; D013154:Spleen / Q000276:immunology*; D013156:Splenectomy; D018074:Vaccines, Conjugate / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D022242:Pneumococcal Vaccines; D011135:Polysaccharides, Bacterial; D018074:Vaccines, Conjugate