title: Evaluation of meningococcal serogroup C conjugate vaccine programs in Canadian children: interim analysis.
abstract: BACKGROUND
  To assess antibody titers afforded by meningococcal C- (MenC) tetanus toxoid conjugate vaccine at 12 months of age in three different immunization schedules.
  
  
  METHODS
  This prospective study included three similar cohorts of healthy infants from 1-dose, 2-dose and 3-dose MenC infant immunization programs. Infants were enrolled at 12 months of age and given the final scheduled dose of MenC-tetanus toxoid conjugate vaccine with sera collected prior to and 1 month after the vaccination. Serum bactericidal activity (SBA) titers ≥ 1:8 were considered protective.
  
  
  RESULTS
  Before the 12 month dose, participants had significantly different protective titers according to the number of prior doses received: 100% (95% CI 97.6-100%) of infants who had 2 prior doses (at 2 and 4 months) were protected compared to 84.0% (76.7-89.3%) of participants with one dose (at 2 months) and 27.6% (21.0-35.4%) of unvaccinated infants. All subjects were protected after the 12 month MenC dose, but titers were higher with prior priming.
  
  
  CONCLUSIONS
  Two MenC doses given in infancy afford optimal protection during the first year of life; however, substantial protection was seen after one dose at 2 months.
authors.affiliation: Vaccine Evaluation Center, BC Children's Hospital, Vancouver, Canada. jbettinger@cw.bc.ca
authors.forename: Julie A
authors.initials: JA
authors.lastname: Bettinger
authors.forename: David W
authors.initials: DW
authors.lastname: Scheifele
authors.forename: Scott A
authors.initials: SA
authors.lastname: Halperin
authors.forename: James D
authors.initials: JD
authors.lastname: Kellner
authors.forename: Otto G
authors.initials: OG
authors.lastname: Vanderkooi
authors.forename: Anthony
authors.initials: A
authors.lastname: Schryvers
authors.forename: Gaston
authors.initials: G
authors.lastname: De Serres
authors.forename: Joenel
authors.initials: J
authors.lastname: Alcantara
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D001770:Blood Bactericidal Activity; D002170:Canada / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000517:prevention & control*; D022401:Meningococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D038542:Neisseria meningitidis, Serogroup C / Q000276:immunology*; D011446:Prospective Studies; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D022401:Meningococcal Vaccines; D018074:Vaccines, Conjugate