ARS | Publication request: Impact of vaccines and vaccination on global control of avian influenza

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 17, 2012
Publication Date: April 1, 2012
Citation: Swayne, D.E., Pavade, G., Hamilton, K. 2012. Impact of vaccines and vaccination on global control of avian influenza. Meeting Abstract. p. 19.

Technical Abstract: High pathogenicity avian influenza (HPAI) and low pathogenicity notifiable avian influenza (LPNAI) in poultry are notifiable to World Organisation for Animal Health (OIE) by its member countries. A comprehensive review of AI control methods has been completed. There may be variation between countries’ responses to avian influenza (AI) outbreak situations based on their economic status (gross domestic product [GDP], agriculture gross domestic product [AGDP], % agriculture contribution to GDP [% AGDP], GDP per capita, gross national income [GNI], human development index [HDI] and Organization for Economic Co-operation and Development [OECD] status), poultry density, performance of veterinary services of a country and various other factors. From countries with HPAI outbreaks during 2002-2010, the study indicated poultry density in least developed countries had significant positive correlation with AI control data suggesting that as poultry density increases there is an increased HPAI outbreak duration, time to eradication and number of outbreaks. The economic indicators GDP, AGDP, % AGDP, GDP per capita, GNI and HDI do not show a direct correlation with the HPAI control data. However, the OECD countries which primarily comprise high income economies, high human resource development, and good governance had significantly fewer HPAI outbreaks, shorter outbreak duration, quicker eradication time and lower mortality rate when compared to non-OECD countries. However, OECD countries had higher culling rates than non-OECD countries suggesting sufficient emergency funding and financial compensation for broad stamping-out programs. The prevention and control of HPAI depends on the quality of veterinary services in each country. The OIE tool for the evaluation of Performance of Veterinary Services (OIE PVS tool) assists the OIE Member Countries to establish their current level of veterinary performance through qualitative evaluation of certain critical core competencies. Competencies like staffing of veterinarians/veterinary paraprofessionals, professional competencies, emergency funding, laboratory diagnostic capacity and resources, transparency, and comprehensive eradication control measures have a negative correlation with HPAI control data suggesting that when veterinary services perform at a higher level there was decreased AI eradication time, mortality rate, culling rate and occurrence of outbreaks. This suggests that countries which are transparent and provide adequate budget for development and maintenance of an efficiently performing veterinary services have better control of HPAI. For vaccine usage as a control tool, >113 billion doses of AI vaccine were used in poultry in 15 countries during 2002-2010. 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. Fewer outbreaks of low pathogenicity notifiable avian influenza (LPNAI) have been reported than HPAI and only six countries used vaccine in control programs for H5/H7 AI vaccine usage.