title: Phase 1 first-in-human studies of the reactogenicity and immunogenicity of a recombinant meningococcal NspA vaccine in healthy adults.
abstract: BACKGROUND
  Neisserial surface protein A (NspA) is a highly conserved, surface-exposed outer membrane protein of Neisseria meningitidis that has been shown to induce a bactericidal immune response in animals against all pathogenic Neisserial serogroups.
  
  
  METHODS
  Healthy 18-50-year-old adults were assigned to receive, in a dose escalating manner, 3 doses of 1 of 5 formulations of an experimental, unfolded, recombinant NspA (rNspA) vaccine or placebo, or 1 dose of commercially available quadravalent (A, C, Y, W-135) meningococcal polysaccharide vaccine (Menomune((R))). Adverse events were collected during the first week post-immunization, prior to the next dose and 1 month after the last dose. Serum for measurement of hematological and biochemical parameters and antibodies by enzyme immunoassay and bactericidal assay were measured before the first dose, prior to the second dose and 1 month after the last dose of vaccine.
  
  
  RESULTS
  The rNspA vaccine was well tolerated by recipients. Injection-site pain was reported more frequently by recipients of the three highest doses of rNspA compared to placebo but at similar rates to the licensed meningococcal polysaccharide vaccine. Adverse events were reported less frequently after subsequent doses in the three-dose series. An antibody rise measured by enzyme immunoassay was elicited with a dose-related increase that reached a maximum with the 125mug dose. Prolongation of the dosing interval between the second and third dose appeared to be associated with increased antibody levels. No bactericidal antibodies were detected after any of the rNspA formulations.
  
  
  CONCLUSIONS
  The unfolded rNspA meningococcal vaccine was well tolerated and immunogenic in healthy adult volunteers but did not elicit bactericidal antibodies.
authors.affiliation: Clinical Trials Research Center, Dalhousie University, The IWK Health Centre, Halifax, NS, Canada. scott.halperin@dal.ca
authors.forename: Scott A
authors.initials: SA
authors.lastname: Halperin
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Langley
authors.forename: Bruce
authors.initials: B
authors.lastname: Smith
authors.forename: Peter
authors.initials: P
authors.lastname: Wunderli
authors.forename: Lisa
authors.initials: L
authors.lastname: Kaufman
authors.forename: Alan
authors.initials: A
authors.lastname: Kimura
authors.forename: Denis
authors.initials: D
authors.lastname: Martin
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000032:analysis / Q000096:biosynthesis; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D022401:Meningococcal Vaccines / Q000009:adverse effects / Q000276:immunology*; D008875:Middle Aged; D014614:Vaccines, Synthetic / Q000009:adverse effects / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D022401:Meningococcal Vaccines; C105506:NspA protein, Neisseria; D014614:Vaccines, Synthetic