title: Total and serotype-specific pneumococcal antibody titres in children with normal and abnormal humoral immunity.
abstract: A heptavalent pneumococcal conjugate vaccine (PCV-7) protects children against invasive pneumococcal disease. The aim of this study was to evaluate immunoglobulin subclass and serotype-specific pneumococcal antibody responses to vaccination in children with a history of recurrent or severe bacterial infections. Pneumococcal IgG, IgG1, IgG2 titres were assayed by ELISA, and nine serotype concentrations measured using a nonaplex bead assay in 145 children investigated for recurrent or severe infections. Children mounted an exclusively IgG1 response after vaccination with two doses of PCV-7 and a dose of 23 valent pneumococcal polysaccharide vaccine (PPV-23), with pneumococcal IgG2 antibody titres remaining low to negligible. Measurement of serotype-specific responses demonstrated that although PCV-7 specific serotype responses increased significantly post-vaccination, specific IgG against two of the serotypes not covered by PCV-7 but only by PPV-23 remained low. We conclude that in contrast to antibody response to natural infection with Pneumococcus or pneumococcal polysaccharide vaccines which are often of a IgG2 subclass, responses in children after PCV-7 are of IgG1 subclass. Serotype-specific IgG were useful in determining the protection against specific pneumococcal strains, and showed that the PPV-23 did not broaden protection against non-PCV-7 serotypes.
authors.affiliation: University of Manchester, Booth Hall Children's Hospital, Charlestown Rd., Manchester, M9 7AA, United Kingdom.
authors.forename: Sharif
authors.initials: S
authors.lastname: Uddin
authors.forename: Ray
authors.initials: R
authors.lastname: Borrow
authors.forename: Mansel R
authors.initials: MR
authors.lastname: Haeney
authors.forename: Andrew
authors.initials: A
authors.lastname: Moran
authors.forename: Rosalind
authors.initials: R
authors.lastname: Warrington
authors.forename: Paul
authors.initials: P
authors.lastname: Balmer
authors.forename: Peter D
authors.initials: PD
authors.lastname: Arkwright
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology*; D000917:Antibody Formation / Q000276:immunology; D000918:Antibody Specificity; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D022401:Meningococcal Vaccines / Q000276:immunology* / Q000627:therapeutic use; D022242:Pneumococcal Vaccines / Q000276:immunology* / Q000627:therapeutic use; D011135:Polysaccharides, Bacterial / Q000276:immunology; D013296:Streptococcus pneumoniae / Q000276:immunology*
chemical_list: C414006:23-valent pneumococcal capsular polysaccharide vaccine; D000907:Antibodies, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D007074:Immunoglobulin G; D022401:Meningococcal Vaccines; D022242:Pneumococcal Vaccines; D011135:Polysaccharides, Bacterial