title: Effect of previous vaccination with pneumococcal conjugate vaccine on pneumococcal polysaccharide vaccine antibody responses.
abstract: During the past 10 years, pneumococcal conjugate vaccine (PCV) has become part of the standard childhood vaccination programme. This may impact upon the diagnosis of polysaccharide antibody deficiency by measurement of anti-polysaccharide immunoglobulin (Ig)G after immunization with unconjugated pneumococcal polysaccharide vaccine (PPV). Indeed, contrary to PPV, PCV induces a T-dependent, more pronounced memory response. The antibody response to PPV was studied retrospectively in patients referred for suspected humoral immunodeficiency. The study population was divided into four subgroups based on age (2-5 years versus ≥ 10 years) and time tested (1998-2005 versus 2010-12). Only 2-5-year-old children tested in 2010-12 had been vaccinated with PCV prior to PPV. The PCV primed group showed higher antibody responses for PCV-PPV shared serotypes 4 and 18C than the unprimed groups. To a lesser extent, this was also found for non-PCV serotype 9N, but not for non-PCV serotypes 19A and 8. Furthermore, PCV-priming elicited a higher IgG2 response. In conclusion, previous PCV vaccination affects antibody response to PPV for shared serotypes, but can also influence antibody response to some non-PCV serotypes (9N). With increasing number of serotypes included in PCV, the diagnostic assessment for polysaccharide antibody deficiency requires careful selection of serotypes that are not influenced by prior PCV (e.g. serotype 8). Further research is needed to identify more serotypes that are not influenced.
authors.affiliation: Department of Pediatrics, University Hospitals Leuven.|Department of Microbiology and Immunology, KU Leuven - University of Leuven.
authors.forename: H
authors.initials: H
authors.lastname: Schaballie
authors.affiliation: Department of Microbiology and Immunology, KU Leuven - University of Leuven.
authors.forename: G
authors.initials: G
authors.lastname: Wuyts
authors.affiliation: Department of Microbiology and Immunology, KU Leuven - University of Leuven.
authors.forename: D
authors.initials: D
authors.lastname: Dillaerts
authors.affiliation: Department of Microbiology and Immunology, KU Leuven - University of Leuven.|Department of Laboratory Medicine, University Hospitals Leuven, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: Frans
authors.affiliation: Department of Microbiology and Immunology, KU Leuven - University of Leuven.
authors.forename: L
authors.initials: L
authors.lastname: Moens
authors.affiliation: Department of Pediatrics, University Hospitals Leuven.
authors.forename: M
authors.initials: M
authors.lastname: Proesmans
authors.affiliation: Department of Pediatrics, University Hospitals Leuven.
authors.forename: F
authors.initials: F
authors.lastname: Vermeulen
authors.affiliation: Department of Pediatrics, University Hospitals Leuven.
authors.forename: K
authors.initials: K
authors.lastname: De Boeck
authors.affiliation: Department of Pediatrics, University Hospitals Leuven.|Department of Microbiology and Immunology, KU Leuven - University of Leuven.
authors.forename: I
authors.initials: I
authors.lastname: Meyts
authors.affiliation: Department of Microbiology and Immunology, KU Leuven - University of Leuven.|Department of Laboratory Medicine, University Hospitals Leuven, Belgium.
authors.forename: X
authors.initials: X
authors.lastname: Bossuyt
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D011008:Pneumococcal Infections / Q000276:immunology / Q000382:microbiology; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D012189:Retrospective Studies; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000276:immunology*; D013997:Time Factors; D014611:Vaccination; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology*
chemical_list: C414006:23-valent pneumococcal capsular polysaccharide vaccine; D000907:Antibodies, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines; D011135:Polysaccharides, Bacterial; D018074:Vaccines, Conjugate
keywords: pneumococcal conjugate vaccine; polysaccharide antibody deficiency; specific antibody deficiency; unconjugated pneumococcal polysaccharide vaccine