Antigenic Cartography of H9 Avian Influenza Virus and Application to Vaccine Selection
Exotic and Emerging Avian Viral Diseases Research Unit
2012 Annual Report
1a.Objectives (from AD-416):
To establish a tool for optimal H9 subtype avian influenza vaccine strain selection by developing an antigenic map of H9 subtype avian influenza virus and correlating vaccine efficacy with antigenic distances.
1b.Approach (from AD-416):
The H9 subtype is the most common avian influenza virus (AIV) subtype in commercial poultry in the world today and is endemic in poultry in Asia and the Middle East where it causes substantial economic losses. H9 AIV is often controlled by vaccination, but there is evidence that like other influenza subtypes, that antigenic variation has occurred resulting in decreased vaccine efficacy. A tool to select the most efficacious vaccines strains by improving antigenic matching is needed to aid control efforts. We aim to develop an antigenic map of H9 AIV with numerous H9 AIVs from around the world using multi-dimensional scaling methods. Once this map is established reference reagents can be selected so that additional isolates can be included. As a second part of the work we will establish criteria for the limits of detection so that antigenic map units can be associated with protection which is critical for vaccine strain selection.
This project is related to objective 1 of this in-house project: Characterize variant and emerging avian influenza viruses in live poultry markets and commercial production systems.
Work on this project was initiated during October of 2011. Initial work has involved producing specific antiserum to 50 H9 subtype avian influenza viruses. This anti-serum is currently being used to conduct tests which will show how closely related the isolates are. Progress is monitored through meetings, phone calls and emails with collaborators and semi-annual reports submitted to the Bi-National Agricultural Research and Development Fund.