title: Age-related immunogenicity of meningococcal polysaccharide vaccine in aboriginal children and adolescents living in a Northern Manitoba reserve community.
abstract: OBJECTIVE
  To determine the total and functional serogroup C antibody response to a quadrivalent meningococcal polysaccharide vaccine in a group of aboriginal infants, children and adolescents. A secondary objective was to determine their prevalence of meningococcal carriage.
  
  
  METHODS
  Open prospective, before and after intervention study.
  
  
  METHODS
  Aboriginal children ages 0.5 to 19.9 years, living in a single Northern community and eligible for a public health immunization campaign conducted in all Manitoba native reserve communities to control a meningococcal serogroup C, electrophoretic type (ET) 15 outbreak. No outbreak cases had occurred in the community at the time of the study.
  
  
  METHODS
  Total serogroup C capsular polysaccharide antibody (CPA) and functional bactericidal antibody (BA) responses were measured by enzyme-linked immunosorbent assay and bactericidal assay, respectively.
  
  
  RESULTS
  Neisseria meningitidis was recovered from the oropharynx of 13 (5.2%) of 249 aboriginal children including 4 (1.6%) serogroup C isolates, all with the designation C:2a:P1.2,5 ET15. Paired sera from 152 children were available for assay. For CPA the geometric mean concentrations and proportions with > or =2 microg/ml before and after immunization were 0.69, 18% and 12.3, 96%, respectively. A significant increase in serum CPA was achieved by children of all ages, with the greatest response occurring after age 11 years. Among infants < lyear old 89% achieved concentrations of > or =2 microg/ml. For BA the pre- and post-vaccine geometric mean titers were 1.02 and 45.9. The response was significantly associated with age. BA titers > or =1:8 were present, before and after immunization, respectively, in 0 and 0% of infants <1 year old, 0 and 20% of 1- to 1.4-year-olds, 0 and 50% of 1.5- to 1.9-year-olds and 1 and 100% of > or =2-year-olds.
  
  
  CONCLUSIONS
  The age-related total and functional group C meningococcal antibody response after quadrivalent polysaccharide vaccine among aboriginals is similar to that reported for Caucasian children. After age 2 all children made excellent CPA and BA responses. In the younger age groups the BA response was blunted but 82 to 95% achieved CPA titers of > or =2 microg/ml.
authors.affiliation: Department of Medical Microbiology, University of Manitoba, Canada. blaw@ms.umanitoba.ca
authors.forename: B J
authors.initials: BJ
authors.lastname: Law
authors.forename: T
authors.initials: T
authors.lastname: Rosenberg
authors.forename: N E
authors.initials: NE
authors.lastname: MacDonald
authors.forename: F E
authors.initials: FE
authors.lastname: Ashton
authors.forename: J C
authors.initials: JC
authors.lastname: Huang
authors.forename: W J
authors.initials: WJ
authors.lastname: King
authors.forename: W J
authors.initials: WJ
authors.lastname: Ferris
authors.forename: G J
authors.initials: GJ
authors.lastname: Gray
mesh_terms: D000293:Adolescent; D044467:American Indian or Alaska Native; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D001428:Bacterial Vaccines / Q000276:immunology*; D002353:Carrier State / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D008350:Manitoba / Q000453:epidemiology; D008589:Meningococcal Infections / Q000453:epidemiology / Q000517:prevention & control*; D022401:Meningococcal Vaccines; D009345:Neisseria meningitidis / Q000145:classification / Q000276:immunology* / Q000302:isolation & purification; D011446:Prospective Studies; D012703:Serotyping
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D022401:Meningococcal Vaccines