title: Opsonophagocytosis versus complement bactericidal killing as effectors following Neisseria meningitidis group C vaccination.
abstract: BACKGROUND
  Opsonophagocytosis and complement-mediated Neisseria meningitidis killing after vaccination were investigated.
  
  
  METHODS
  Twelve seronegative healthy volunteers received one dose of polysaccharide A/C vaccine and were followed for 3 years. Ex vivo serum killing rates with polymorphonuclear cells (PMN) and/or complement were performed at 0, 1.5, 6, 12, 18, 24, 30 and 36 months.
  
  
  RESULTS
  High mean total and median bactericidal antibodies were detected over time in all subjects. Considerable reduction of the initial inoculum was obtained only in the presence of complement, with or without PMN (with significant differences compared to curves without complement) a long time after vaccination.
  
  
  CONCLUSIONS
  PMN did not increase post-vaccination bacterial killing, suggesting that antibody complement-mediated killing, and not opsonophagocytosis, is the main immune effector of the vaccine protection against N. meningitidis.
authors.affiliation: Dept of Microbiology I, School of Medicine, Complutense University, Avda Complutense s/n, E-28040 Madrid, Spain.
authors.forename: M L
authors.initials: ML
authors.lastname: Gomez-Lus
authors.forename: M J
authors.initials: MJ
authors.lastname: Giménez
authors.forename: J A
authors.initials: JA
authors.lastname: Vázquez
authors.forename: L
authors.initials: L
authors.lastname: Aguilar
authors.forename: L
authors.initials: L
authors.lastname: Anta
authors.forename: S
authors.initials: S
authors.lastname: Berrón
authors.forename: B
authors.initials: B
authors.lastname: Laguna
authors.forename: J
authors.initials: J
authors.lastname: Prieto
mesh_terms: D001770:Blood Bactericidal Activity; D003165:Complement System Proteins / Q000276:immunology*; D006801:Humans; D008297:Male; D022401:Meningococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D038542:Neisseria meningitidis, Serogroup C / Q000276:immunology*; D009895:Opsonin Proteins / Q000276:immunology*; D010587:Phagocytosis / Q000276:immunology*; D012698:Serologic Tests; D013997:Time Factors
chemical_list: D022401:Meningococcal Vaccines; D009895:Opsonin Proteins; D003165:Complement System Proteins