title: Antibody persistence after primary and booster doses of a quadrivalent meningococcal conjugate vaccine in adolescents.
abstract: BACKGROUND
  The aim of this study was to evaluate antibody persistence 5 years after primary vaccination with the quadrivalent meningococcal conjugate vaccines MenACWY-CRM or MenACWY-D and 2 years after a booster dose of MenACWY-CRM, in the context of a phase 3 study.
  
  
  METHODS
  Subjects (aged 19.2 ± 2.3 years) were assigned to 5 groups according to whether they had previously received primary vaccination (at 14.2 ± 2.2 years) with MenACWY-CRM (N = 131) or MenACWY-D (N = 76), a booster dose of MenACWY-CRM 3 years after primary vaccination with MenACWY-CRM (N = 44) or MenACWY-D (N = 31) or no vaccination (N = 107). The immunogenicity measures were percentages of subjects with serum bactericidal activity (hSBA) ≥ 1:8 for serogroups A, C, W and Y and hSBA geometric mean titers. Comparisons with age-matched, vaccine-naive subjects were performed.
  
  
  RESULTS
  A majority of subjects vaccinated 5 years previously maintained hSBA ≥ 1:8 against serogroups C, W and Y in the MenACWY-CRM (59%-82%) and MenACWY-D groups (54%-73%); this was lower for serogroup A in both groups. There was a decline in antibody titers after primary vaccination, especially in the first 2 years postprimary vaccination, with steady concentrations during the next 3 years. Two years after MenACWY-CRM booster vaccination the percentages of subjects with hSBA ≥ 1:8 ranged from 77% to 100% across serogroups and geometric mean titers were 2.5- to 8-fold higher than prebooster values across serogroups.
  
  
  CONCLUSIONS
  Booster vaccination with MenACWY-CRM elicited a robust immune response during the 2-year follow-up period, irrespective of previous vaccination.
authors.affiliation: From the *Kaiser Permanente Vaccine Study Center, Oakland, CA; †Primary Physicians Research, Pittsburgh, PA; ‡Kentucky Pediatric and Adult Research, Bardstown, KY; and §Novartis Vaccines, Cambridge, MA.
authors.forename: Roger
authors.initials: R
authors.lastname: Baxter
authors.forename: Keith
authors.initials: K
authors.lastname: Reisinger
authors.forename: Stanley L
authors.initials: SL
authors.lastname: Block
authors.forename: Sandra
authors.initials: S
authors.lastname: Percell
authors.forename: Tatjana
authors.initials: T
authors.lastname: Odrljin
authors.forename: Peter M
authors.initials: PM
authors.lastname: Dull
authors.forename: Igor
authors.initials: I
authors.lastname: Smolenov
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood*; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007117:Immunization, Secondary / Q000009:adverse effects; D008297:Male; D022401:Meningococcal Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D009345:Neisseria meningitidis / Q000276:immunology*; D015610:Serum Bactericidal Test; D013997:Time Factors; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D022401:Meningococcal Vaccines; D018074:Vaccines, Conjugate