title: Five-year Antibody Persistence and Booster Response to a Single Dose of Meningococcal A, C, W and Y Tetanus Toxoid Conjugate Vaccine in Adolescents and Young Adults: An Open, Randomized Trial.
abstract: BACKGROUND
  We evaluated antibody persistence after 1 dose of meningococcal serogroups ACWY tetanus toxoid (MenACWY-TT) or diphtheria toxoid (MenACWY-DT) conjugate vaccines and subsequent booster responses to MenACWY-TT.
  
  
  METHODS
  In the initial phase II, open, multicenter study (NCT00454909), 872 participants aged 10-25 years received 1 MenACWY-TT or MenACWY-DT dose. In this study (NCT00715910), antibody persistence was evaluated at years 1, 3 and 5 by serum bactericidal activity assays using human complement (hSBA). At year 5, all participants received a MenACWY-TT booster dose. Immune responses at 1-month postbooster were compared with a control group including 101 participants aged 15-30 years who received a primary MenACWY-TT dose. Solicited and unsolicited adverse events were recorded for 4 and 31 days, respectively, followed by a 6-month extended safety follow-up.
  
  
  RESULTS
  At year 5, ≥79.5% of MenACWY-TT-primed (n = 170) and MenACWY-DT-primed (n = 45) participants had hSBA titers ≥1:8 for MenC, MenW and MenY, and ≥37.5% for MenA. For all serogroups, ≥85.7% and ≥67.1% of MenACWY-TT booster and primary dose recipients exhibited vaccine responses 1-month postmvaccination, respectively. Geometric mean titers were potentially higher in primed versus naive participants, with no potential difference between MenACWY-TT-primed and MenACWY-DT-primed participants (exploratory analyses). MenACWY-TT had a clinically acceptable safety profile.
  
  
  CONCLUSIONS
  Before the booster dose administration at year 5, hSBA-MenC, -MenW and -MenY antibody persistence was observed in most participants. However, only ≥37.5% of MenACWY-TT and 44.4% of MenACWY-DT recipients retained hSBA-MenA titers ≥1:8. MenACWY-TT booster doses elicited robust anamnestic responses, irrespective of the priming vaccine, and were well tolerated.
authors.affiliation: From the *Kaiser Permanente Vaccine Study Center, Oakland, California; †Vaccines Discovery & Development, GSK Vaccines, King of Prussia, Pennsylvania; †Pharma Europe & EMAP, GSK Pharmaceuticals India Ltd, Bangalore, India; and §Clinical R&D, GSK Vaccines, Wavre, Belgium.
authors.forename: Roger
authors.initials: R
authors.lastname: Baxter
authors.forename: Yaela
authors.initials: Y
authors.lastname: Baine
authors.forename: Devayani
authors.initials: D
authors.lastname: Kolhe
authors.forename: Carmen I
authors.initials: CI
authors.lastname: Baccarini
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Miller
authors.forename: Marie
authors.initials: M
authors.lastname: Van der Wielen
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D008297:Male; D008589:Meningococcal Infections / Q000517:prevention & control*; D022401:Meningococcal Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D009345:Neisseria meningitidis / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; C525703:MenACWY; D022401:Meningococcal Vaccines; D018074:Vaccines, Conjugate