title: Five-year Antibody Persistence and Safety After a Single Dose of Combined Haemophilus influenzae Type B Neisseria meningitidis Serogroup C-Tetanus Toxoid Conjugate Vaccine in Haemophilus influenzae Type B-primed Toddlers.
abstract: BACKGROUND
  Antibody persistence is evaluated in healthy Australian children 4 and 5 years postvaccination with a single dose of combined Haemophilus influenzae type b-Neisseria meningitidis serogroup C tetanus toxoid conjugate vaccine (Hib-MenC-TT) compared with separately administered Hib-TT and MenC-CRM197 vaccines (Hib + MCC).
  
  
  METHODS
  This is another follow-up of a phase III, open, randomized, controlled study (NCT00326118), in which 433 Hib-primed but MenC naïve toddlers aged 12-18 months were randomized 3:1 to receive Hib-MenC-TT or Hib + MCC vaccines. Protection against (1) MenC was measured by serum bactericidal antibody assay using rabbit complement (rSBA) and (2) Hib was measured by enzyme-linked immunosorbent assay of antibodies to polyribosylribitol phosphate (anti-PRP). Study children were assessed for any potentially vaccine-related serious adverse events at each persistence study visit.
  
  
  RESULTS
  The according-to-protocol cohorts for persistence at years 4 and 5 included 282 and 263 children, respectively. The percentages of children with rSBA-MenC titers ≥1:8 at years 4 and 5 were 12.5% and 19.0%, respectively, in the Hib-MenC group; and 12.3% and 25.0% in the Hib + MCC group. All children in each group had anti-PRP concentrations ≥0.15 μg/mL at year 5. Exploratory analyses suggested no potential differences between groups in rSBA-MenC or anti-PRP antibody persistence. No vaccine-related serious adverse events were reported.
  
  
  CONCLUSIONS
  Antibody persistence was similar for years 4 and 5 after Hib-MenC-TT or Hib + MCC vaccination, with the majority of children retaining anti-PRP antibody concentrations ≥0.15 μg/mL at both timepoints. The percentage of children retaining rSBA-MenC titers ≥1:8 was low (≤25%), suggesting that a MenC booster dose may be warranted before adolescence.
authors.affiliation: From the *National Centre for Immunisation Research and Surveillance (NCIRS), The Children's Hospital at Westmead, University of Sydney, Sydney, New South Wales, Australia; †Vaccine and Immunisation Research Group, Murdoch Children's Research Institute, University of Melbourne, Carlton, Australia; ‡School of Population and Global Health, University of Melbourne, Carlton, Australia; §Canberra Hospital, Woden, Canberra, Australia; ¶School of Paediatrics and Child Health, University of Western Australia, Perth, Australia; ‖Telethon Kids Institute, Perth, Australia; **Princess Margaret Hospital for Children, Perth, Australia; ††Vaccine Trials Group, University of Western Australia Centre for Child Health Research and Vaccine Trials Group, Telethon Kids Institute for Child Health Research, Perth, Australia; ‡‡Royal Children's Hospital, Brisbane, Queensland, Australia; §§School of Paediatrics and Reproductive Health, Robinson Research Institute, Women's and Children's Hospital, University of Adelaide, Adelaide, Australia; ¶¶GSK Vaccines, Wavre, Belgium; ‖‖GSK Pharmaceuticals Limited, Bangalore, Karnataka, India; and ***GSK Vaccines, King of Prussia, Philadelphia, Pennsylvania.
authors.forename: Robert
authors.initials: R
authors.lastname: Booy
authors.forename: Terry
authors.initials: T
authors.lastname: Nolan
authors.forename: Graham
authors.initials: G
authors.lastname: Reynolds
authors.forename: Peter
authors.initials: P
authors.lastname: Richmond
authors.forename: Michael
authors.initials: M
authors.lastname: Nissen
authors.forename: Helen
authors.initials: H
authors.lastname: Marshall
authors.forename: Tanya
authors.initials: T
authors.lastname: Stoney
authors.forename: Marie
authors.initials: M
authors.lastname: Van Der Wielen
authors.forename: Devayani
authors.initials: D
authors.lastname: Kolhe
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Miller
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D018073:Haemophilus Vaccines / Q000009:adverse effects* / Q000276:immunology*; D006801:Humans; D008297:Male; D013745:Tetanus Toxoid / Q000009:adverse effects* / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000009:adverse effects / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D018073:Haemophilus Vaccines; C527605:Hib-MenCY-TT vaccine; D013745:Tetanus Toxoid; D018074:Vaccines, Conjugate