Table of Contents
Influenza Research and Treatment
Volume 2010 (2010), Article ID 489213, 10 pages
Research Article

Evaluation of a Subunit H5 Vaccine and an Inactivated H5N2 Avian Influenza Marker Vaccine in Ducks Challenged with Vietnamese H5N1 Highly Pathogenic Avian Influenza Virus

1School of Veterinary and Biomedical Sciences, Murdoch University, 90 South Street Murdoch, WA 6150, Australia
2Agri-Food and Veterinary Authority of Singapore, 5 Maxwell Road, Singapore 069110
3Department of Microbiology, The University of Hong Kong, Pathology Building, Queen Mary Hospital Compound, Pokfulam, Hong Kong
4Temasek Life Sciences Laboratory, 1, Research Link, National University of Singapore, Singapore 117604

Received 11 January 2010; Accepted 8 April 2010

Academic Editor: Ayato Takada

Copyright © 2010 Tze-Hoong Chua 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 protective efficacy of a subunit avian influenza virus H5 vaccine based on recombinant baculovirus expressed H5 haemagglutinin antigen and an inactivated H5N2 avian influenza vaccine combined with a marker antigen (tetanus toxoid) was compared with commercially available inactivated H5N2 avian influenza vaccine in young ducks. Antibody responses, morbidity, mortality, and virus shedding were evaluated after challenge with a Vietnamese clade 1 H5N1 HPAI virus [A/VN/1203/04 (H5N1)] that was known to cause a high mortality rate in ducks. All three vaccines, administered with water-in-oil adjuvant, provided significant protection and dramatically reduced the duration and titer of virus shedding in the vaccinated challenged ducks compared with unvaccinated controls. The H5 subunit vaccine was shown to provide equivalent protection to the other two vaccines despite the H5 antibody responses in subunit vaccinated ducks being significantly lower prior to challenge. Ducks vaccinated with the H5N2 marker vaccine consistently produced antitetanus toxoid antibody. The two novel vaccines have attributes that would enhance H5N1 avian influenza surveillance and control by vaccination in small scale and village poultry systems.