A sensitive retroviral pseudotype assay for influenza H5N1-neutralizing antibodies.
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.
Temperton
Nigel J
NJ
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
Hoschler
Katja
K
Major
Diane
D
Nicolson
Carolyn
C
Manvell
Ruth
R
Hien
Vo Minh
VM
Ha
Do Quang
do Q
de Jong
Menno
M
Zambon
Maria
M
Takeuchi
Yasuhiro
Y
Weiss
Robin A
RA
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
D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; C109963:hemagglutinin, avian influenza A virus