Title: Emergence of H5N1 high pathogenicity avian influenza strains in Indonesia that are resistant to vaccines Authors
Submitted to: American Veterinary Medical Association Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2013
Publication Date: July 20, 2013
Citation: Swayne, D.E., Spackman, E., Jadhao, S., Indriani, R., Yupiana, Y., Suarez, D.L. 2013. Emergence of H5N1 high pathogenicity avian influenza strains in Indonesia that are resistant to vaccines [abstract]. Abstracts of the Annual meeting of American Veterinary Medical Association of Avian Pathologists and the American Veterinary Medical Association, Chicago, Illinois, July 20-23,2013. p.446. Technical Abstract: Vaccines have been used to protect poultry in Asia against H5N1 high pathogenicity avian influenza (HPAI) since 2002. Reports of vaccine “failures” began to emerge in 2006 in Indonesia, with identification of clinical disease consistent with HPAI or isolation of H5N1 HPAIV in vaccinated flocks or in regions with vaccine coverage. In this study, H5N1 HPAI field viruses from Indonesia were examined genetically and antigenically to identify variants, and three viruses were selected for challenge studies against classic H5 avian influenza vaccine seed strains. An antigenic drift variant H5N1 HPAI virus (A/Chicken/West Java/PWT-WIJ/2006 [PWT/06]) was identified in Indonesia that was not protected by classic H5 AI vaccines. Usage of the parent HPAI virus protected chickens from lethal challenge. Reverse genetics (rg) based low pathogenicity avian influenza (LPAI) virus seed strains were constructed using the hemagglutinin gene of A/Chicken/West Java/PWT-WIJ/2006 (H5N1), and one of the clones protected chickens against challenge with the HPAI parent strain. These studies indicate that antigenic variants did emerge in Indonesia following widespread H5 avian influenza vaccine usage. New vaccine seed strains to produce inactivated vaccines can be selected based on the HPAI parent virus. To offer a better alternative for biosecurity, manufacturing and prevent vaccine failures, antigenically matched rg-LPAI next generation efficacious high growth vaccine seed strains can be generated rapidly using influenza reverse genetics.