title: A sensitive retroviral pseudotype assay for influenza H5N1-neutralizing antibodies.
abstract: BACKGROUND
  The World Health Organisation (WHO) recommended the development of simple, safe, sensitive and specific neutralization assays for avian influenza antibodies. We have used retroviral pseudotypes bearing influenza H5 hemagglutinin (HA) as safe, surrogate viruses for influenza neutralization assays which can be carried out at Biosafety Level 2.
  
  
  RESULTS
  Using our assay, sera from patients who had recovered from infection with influenza H5N1, and sera from animals experimentally immunized or infected with H5 tested positive for the presence of neutralizing antibodies to H5N1. Pseudotype neutralizing antibody titers were compared with titers obtained by hemagglutinin inhibition (HI) assays and microneutralization (MN) assays using live virus, and showed a high degree of correlation, sensitivity and specificity.
  
  
  CONCLUSIONS
  The pseudotype neutralization assay is as sensitive as horse erythrocyte HI and MN for the detection of antibodies to H5N1. It is safer, and can be applied in a high-throughput format for human and animal surveillance and for the evaluation of vaccines.
authors.affiliation: MRC/UCL Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London, 46 Cleveland Street, London, United Kingdom. nigel.temperton@ucl.ac.uk
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Temperton
authors.forename: Katja
authors.initials: K
authors.lastname: Hoschler
authors.forename: Diane
authors.initials: D
authors.lastname: Major
authors.forename: Carolyn
authors.initials: C
authors.lastname: Nicolson
authors.forename: Ruth
authors.initials: R
authors.lastname: Manvell
authors.forename: Vo Minh
authors.initials: VM
authors.lastname: Hien
authors.forename: Do Quang
authors.initials: do Q
authors.lastname: Ha
authors.forename: Menno
authors.initials: M
authors.lastname: de Jong
authors.forename: Maria
authors.initials: M
authors.lastname: Zambon
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Robin A
authors.initials: RA
authors.lastname: Weiss
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D005260:Female; D005289:Ferrets; D006385:Hemagglutination Inhibition Tests; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000276:immunology*; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D005585:Influenza in Birds / Q000175:diagnosis / Q000276:immunology; D007251:Influenza, Human / Q000175:diagnosis / Q000276:immunology; D008297:Male; D009500:Neutralization Tests / Q000379:methods; D009976:Orthomyxoviridae Infections / Q000175:diagnosis / Q000276:immunology; D011200:Poultry; D012190:Retroviridae / Q000235:genetics; D012680:Sensitivity and Specificity; D012756:Sheep
chemical_list: D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; C109963:hemagglutinin, avian influenza A virus