title: Haemophilus influenzae type b reemergence after combination immunization.
abstract: An increase in Haemophilus influenzae type b (Hib) in British children has been linked to the widespread use of a diphtheria/tetanus/acellular pertussis combination vaccine (DTaP-Hib). We measured anti-polyribosyl-ribitol phosphate antibody concentration and avidity before and after a Hib booster in 176 children 2-4 years of age who had received 3 doses of DTP-Hib (either DT whole cell pertussis-Hib or DTaP-Hib) combination vaccine in infancy. We also measured pharyngeal carriage of Hib. Antibody concentrations before and avidity indices after vaccination were low (geometric mean concentration 0.46 mug/mL, 95% confidence interval [CI] 0.36-0.58; geometric mean avidity index 0.16, 95% CI 0.14-0.18) and inversely related to the number of previous doses of DTaP-Hib (p = 0.02 and p<0.001, respectively). Hib was found in 2.1% (95% CI 0.7%-6.0%) of study participants. Our data support an association between DTaP-Hib vaccine combinations and clinical Hib disease through an effect on antibody concentration and avidity.
authors.affiliation: St George's University of London, London, United Kingdom.
authors.forename: Nik G
authors.initials: NG
authors.lastname: Johnson
authors.forename: Jens U
authors.initials: JU
authors.lastname: Ruggeberg
authors.forename: Gail F
authors.initials: GF
authors.lastname: Balfour
authors.forename: Y Chen
authors.initials: YC
authors.lastname: Lee
authors.forename: Helen
authors.initials: H
authors.lastname: Liddy
authors.forename: Diane
authors.initials: D
authors.lastname: Irving
authors.forename: Joanna
authors.initials: J
authors.lastname: Sheldon
authors.forename: Mary P E
authors.initials: MP
authors.lastname: Slack
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Pollard
authors.forename: Paul T
authors.initials: PT
authors.lastname: Heath
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D000915:Antibody Affinity; D016667:Bacterial Capsules; D002675:Child, Preschool; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines / Q000276:immunology*; D006192:Haemophilus Infections / Q000453:epidemiology* / Q000276:immunology*; D018073:Haemophilus Vaccines / Q000276:immunology*; D019741:Haemophilus influenzae type b / Q000276:immunology*; D006801:Humans; D007114:Immunization / Q000379:methods; D010614:Pharynx / Q000821:virology; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D018709:Statistics, Nonparametric; D006113:United Kingdom / Q000453:epidemiology; D018074:Vaccines, Conjugate / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D011135:Polysaccharides, Bacterial; D018074:Vaccines, Conjugate