Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 2/22/2017
Publication Date: 3/7/2017
Citation: Swayne, D.E. 2017. Periodic updating of avian influenza vaccines is necessary to maintain effectiveness in the field. In: Proceedings of the The Association of Production Directives and Managers of the Poultry Producer Companies of Mexico 2017 Conference, March 7-9, 2017, Queretaro, Mexico. 2017 CDROM.
Technical Abstract: The impact of avian influenza on poultry production is undeniable. Field outbreaks of H5N1 HPAI have occurred in vaccinated flocks from both failure of the vaccines (i.e. vaccine efficacy) and failure in administration or immune response of the target species (i.e. vaccination effectiveness). Antigenic drift in field HPAI viruses has resulted in failure of protection by classic H5 vaccines strains in Mexico, China, Egypt, Indonesia, Hong Kong and Vietnam. This challenge has been met by developing new vaccine strains that provide protection against ever changing viruses. A comprehensive review of AI control methods by World Organization for Animal Health has been completed. From 2002-2010, >113 billion doses of AI vaccine were used in poultry in 15 countries. The majority of vaccine (>91%) was used in China while significant amounts were used in Egypt, Indonesia, and Vietnam. Implementation of vaccination in these four countries occurred after H5N1 HPAI became endemic in domestic poultry and vaccination did not result in the endemic infections. The other 11 countries used less than 1% of the vaccine. Inactivated AI vaccines accounted for 95.5% and live recombinant virus vaccines for 4.5% of vaccine used. Clinical disease and mortality were prevented in chickens, and rural livelihoods and food security were maintained by using vaccines during HPAI outbreaks. Better surveillance is needed in vaccinated flocks and regions to identify foci of infection for eradication.