title: Safety and immunogenicity of a serogroups A/C Neisseria meningitidis oligosaccharide-protein conjugate vaccine in young children. A randomized controlled trial.
abstract: OBJECTIVE
  To assess the safety and immunogenicity of a bivalent serogroups A/C meningococcal oligosaccharide-protein conjugate vaccine compared with the licensed meningococcal polysaccharide vaccine.
  
  
  METHODS
  Randomized controlled trial.
  
  
  METHODS
  Ninety healthy 18- to 24-month-old children who were seen at a southern California Kaiser Permanente clinic.
  
  
  METHODS
  Vaccination with either the meningococcal conjugate vaccine (at 1 of 2 dosages) or the polysaccharide vaccine, with 2 doses given 2 months apart.
  
  
  METHODS
  Immune response to each vaccine dose as determined by measurement of serogroup-specific total antibodies by enzyme-linked immunosorbent assay (ELISA) and by assessment of serum bactericidal activity.
  
  
  RESULTS
  Both vaccines appeared to be safe, and nearly all children responded with greater than 4-fold increases in antibody levels. The 2 dosages of the conjugate vaccine induced similar antibody responses; therefore, the data for the 2 conjugate vaccine groups were combined. Following 2 doses, ELISA antibody levels against group C meningococcus were significantly higher in conjugate vaccine recipients than in polysaccharide vaccine recipients (16.66 microg/mL vs. 8.31 microgm/mL; P<.001), but antibody levels against group A were not significantly different 22.75 microg/mL vs 21.24 microg/mL; P=.70). The serum bactericidal assays showed striking differences between the conjugate and polysaccharide vaccine groups. Geometric mean serum bactericidal titers were significantly higher in conjugate vaccine recipients (755.6 vs 37.6 for group A, P<.001; 3197.9 vs 11.4 for group C, P<.001).
  
  
  CONCLUSIONS
  The immune response induced by this meningococcal oligosaccharide-protein conjugate vaccine was qualitatively different from that induced by the polysaccharide vaccine, and the antibodies it elicited provided greater functional activity.
authors.affiliation: UCLA Center for Vaccine Research, Harbor-UCLA Medical Center, Torrance, California 90502, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Lieberman
authors.forename: S S
authors.initials: SS
authors.lastname: Chiu
authors.forename: V K
authors.initials: VK
authors.lastname: Wong
authors.forename: S
authors.initials: S
authors.lastname: Partidge
authors.forename: S J
authors.initials: SJ
authors.lastname: Chang
authors.forename: C Y
authors.initials: CY
authors.lastname: Chiu
authors.forename: L L
authors.initials: LL
authors.lastname: Gheesling
authors.forename: G M
authors.initials: GM
authors.lastname: Carlone
authors.forename: J I
authors.initials: JI
authors.lastname: Ward
mesh_terms: D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D001770:Blood Bactericidal Activity; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007223:Infant; D008589:Meningococcal Infections / Q000517:prevention & control; D022401:Meningococcal Vaccines; D009345:Neisseria meningitidis / Q000145:classification / Q000276:immunology*; D012703:Serotyping; D014611:Vaccination; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D022401:Meningococcal Vaccines; D018074:Vaccines, Conjugate