Table of Contents
Influenza Research and Treatment
Volume 2013 (2013), Article ID 286158, 9 pages
Research Article

Comparative Serological Assays for the Study of H5 and H7 Avian Influenza Viruses

1Viral Pseudotype Unit, Medway School of Pharmacy, University of Kent, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
2FAO-OIE and National Reference Laboratory for Newcastle Disease and Avian Influenza, Istituto Zooprofilattico delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy

Received 28 June 2013; Accepted 16 August 2013

Academic Editor: Prasert Auewarakul

Copyright © 2013 Eleonora Molesti et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The nature of influenza virus to randomly mutate and evolve into new types is an important challenge in the control of influenza infection. It is necessary to monitor virus evolution for a better understanding of the pandemic risk posed by certain variants as evidenced by the highly pathogenic avian influenza (HPAI) viruses. This has been clearly recognized in Egypt following the notification of the first HPAI H5N1 outbreak. The continuous circulation of the virus and the mass vaccination programme undertaken in poultry have resulted in a progressive genetic evolution and a significant antigenic drift near the major antigenic sites. In order to establish if vaccination is sufficient to provide significant intra- and interclade cross-protection, lentiviral pseudotypes derived from H5N1 HPAI viruses (A/Vietnam/1194/04, A/chicken/Egypt-1709-01/2007) and an antigenic drift variant (A/chicken/Egypt-1709-06-2008) were constructed and used in pseudotype-based neutralization assays (pp-NT). pp-NT data obtained was confirmed and correlated with HI and MN assays. A panel of pseudotypes belonging to influenza Groups 1 and 2, with a combination of reporter systems, was also employed for testing avian sera in order to support further application of pp-NT as an alternative valid assay that can improve avian vaccination efficacy testing, vaccine virus selection, and the reliability of reference sera.