title: Immunogenicity of 2 serogroup B outer-membrane protein meningococcal vaccines: a randomized controlled trial in Chile.
abstract: BACKGROUND
  Meningococcal disease occurs worldwide, and serogroup B disease accounts for a large proportion of cases. Although persons younger than 4 years are at greatest risk for serogroup B meningococcal disease, vaccine efficacy has not been demonstrated in this age group.
  
  
  OBJECTIVE
  To evaluate serum bactericidal activity (SBA) against homologous vaccine type strains and a heterologous Chilean epidemic strain of Neisseria meningitidis as a potential correlate for vaccine efficacy.
  
  
  METHODS
  Double-blind, randomized controlled trial conducted between March 14 and July 20, 1994. All blood samples were taken by December 1994.
  
  
  METHODS
  Santiago, Chile, where a clonal serogroup B meningococcal disease epidemic began in 1993.
  
  
  METHODS
  Infants younger than 1 year (n = 187), children aged 2 to 4 years (n = 183), and adults aged 17 to 30 years (n = 173).
  
  
  METHODS
  Participants received 3 doses of outer-membrane protein (OMP) meningococcal vaccine developed in either Cuba or Norway or a control vaccine, with each dose given 2 months apart. Blood samples were obtained at baseline, prior to dose 3, and at 4 to 6 weeks after dose 3.
  
  
  METHODS
  Immune response, defined as a 4-fold or greater rise in SBA titer 4 to 6 weeks after dose 3 compared with prevaccination titer.
  
  
  RESULTS
  Children and adult recipients of either meningococcal vaccine were more likely than controls to develop an immune response to the heterologous epidemic strain. After 3 doses of vaccine, 31% to 35% of children responded to the vaccine vs 5% to placebo; 37% to 60% of adults responded to vaccine vs 4% to placebo (P<.05 vs control for all). Infants, however, did not respond. In contrast, against homologous vaccine type strains, the response rate was 67% or higher among children and adults and 90% or higher among infants (P<.001 vs control for all). Subsequent SBA against 7 isogenic homologous target strains identified class 1 OMP as the immunodominant antigen.
  
  
  CONCLUSIONS
  These data suggest that neither serogroup B OMP meningococcal vaccine would confer protection during a heterologous epidemic. However, epidemic strain-specific vaccines homologous for class 1 OMP are promising candidates for the control of epidemic serogroup B meningococcal disease.
authors.affiliation: Centers for Disease Control and Prevention, Meningitis and Special Pathogens Branch, Atlanta, GA 30333, USA. jwt0@cdc.gov
authors.forename: J W
authors.initials: JW
authors.lastname: Tappero
authors.forename: R
authors.initials: R
authors.lastname: Lagos
authors.forename: A M
authors.initials: AM
authors.lastname: Ballesteros
authors.forename: B
authors.initials: B
authors.lastname: Plikaytis
authors.forename: D
authors.initials: D
authors.lastname: Williams
authors.forename: J
authors.initials: J
authors.lastname: Dykes
authors.forename: L L
authors.initials: LL
authors.lastname: Gheesling
authors.forename: G M
authors.initials: GM
authors.lastname: Carlone
authors.forename: E A
authors.initials: EA
authors.lastname: Høiby
authors.forename: J
authors.initials: J
authors.lastname: Holst
authors.forename: H
authors.initials: H
authors.lastname: Nøkleby
authors.forename: E
authors.initials: E
authors.lastname: Rosenqvist
authors.forename: G
authors.initials: G
authors.lastname: Sierra
authors.forename: C
authors.initials: C
authors.lastname: Campa
authors.forename: F
authors.initials: F
authors.lastname: Sotolongo
authors.forename: J
authors.initials: J
authors.lastname: Vega
authors.forename: J
authors.initials: J
authors.lastname: Garcia
authors.forename: P
authors.initials: P
authors.lastname: Herrera
authors.forename: J T
authors.initials: JT
authors.lastname: Poolman
authors.forename: B A
authors.initials: BA
authors.lastname: Perkins
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines / Q000276:immunology*; D001770:Blood Bactericidal Activity; D002675:Child, Preschool; D002677:Chile; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D016056:Immunodominant Epitopes; D007223:Infant; D008297:Male; D008589:Meningococcal Infections / Q000517:prevention & control; D022401:Meningococcal Vaccines; D009345:Neisseria meningitidis / Q000145:classification* / Q000235:genetics / Q000276:immunology*; D012703:Serotyping
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D016056:Immunodominant Epitopes; D022401:Meningococcal Vaccines