A multiplex assay for the evaluation of avian influenza H5 and H7 neutralizing antibodies directed against haemagglutinin

The continuous rapid evolution of LPAI and HPAI H5 and H7 influenza viruses in domestic poultry has major public and animal health

implications. We have described a modular multiplex assay for the study of neutralizing antibodies directed against influenza H5 and H7.

This assay permits the measurement of neutralizing antibody responses against two antigenically distinct HA envelopes in the same serum/

plasma sample. Sera obtained from chickens vaccinated with a monovalent H5N2 vaccine, a bivalent H7N1/H5N9 vaccine, or infected with

an H7N3 virus were evaluated in this assay and the results correlated strongly with HI data. For the sera obtained from chickens vaccinated

with a bivalent vaccine the neutralization assay was performed with a single pseudotype virus (H5 or H7) as a monoplex assay or with the two viruses mixed 1:1 (H5 and H7) as a multiplex assay and the neutralizing antibody profiles were found to be equivalent. This multiplex

assay is undergoing further evaluation as a routine screening method for the detection of antibodies against notifiable H5 and H7 infections

in birds.