Title: Success factors for avian influenza vaccine use in poultry and potential impact at the wild bird-agricultural interface Authors
Submitted to: EcoHealth
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 12, 2013
Publication Date: September 12, 2013
Citation: Swayne, D.E., Spackman, E., Pantin Jackwood, M.J. 2013. Success factors for avian influenza vaccine use in poultry and potential impact at the wild bird-agricultural interface. EcoHealth. 11:94-108. DOI:10.1007/s10393-013-0861-3. Interpretive Summary: Thirty-two outbreaks of bird flu have occurred in poultry since 1959. The current H5N1 bird flu outbreak has spilled over to also affect wild birds. Traditional culling programs in poultry have resulted in eradication of most HPAI outbreaks but vaccination of poultry was added during five outbreaks. Over 113 billion doses of AI vaccine was used in poultry from 2002-2010. Most of the vaccine was used in China (91%), Egypt (4.7%), Indonesia (2.3%), and Vietnam (1.4%) where vaccination programs have attempted to vaccinate all poultry in the countries. The 10 other countries have used less than 1% of the vaccine and have focused the vaccine to specific types of poultry in small geographic regions. Failures have resulted from improper vaccination and poor quality vaccines. Vaccination is not feasible in wild bird.
Technical Abstract: Thirty-two epizootics of high pathogenicity avian influenza (HPAI) have been reported in poultry and other birds since 1959. The ongoing H5N1 HPAI epizootic that began in 1996 has also spilled over to infect wild birds. Traditional stamping-out programs in poultry have resulted in eradication of most HPAI epizootics. However, vaccination of poultry was added as a control tool in 1995 and has been used during five epizootics. Over 113 billion doses of AI vaccine have been used in poultry from 2002-2010 as oil-emulsified, inactivated whole AIV vaccines (95.5%) and live vectored vaccines (4.5%). Over 99% of the vaccine has been used in the four H5N1 HPAI enzootic countries: China including Hong Kong (91%), Egypt (4.7%), Indonesia (2.3%), and Vietnam (1.4%) where vaccination programs have been nationwide and routine to all poultry. The 10 other countries have used less than 1% of the vaccine and have administered the vaccine in a focused, risk-based manner. Most vaccine “failures” have resulted from problems in the vaccination process; i.e. failure to adequately administer the vaccine to at risk poultry resulting in lack of population immunity, while fewer failures have resulted from antigenic drift of field viruses away from the vaccine viruses. It is currently not feasible to vaccinate wild birds against H5N1 HPAI, but naturally occurring infections with H5 low pathogenicity avian influenza viruses may generate cross protective immunity against H5N1 HPAI. The most feasible method to prevent and control H5N1 HPAI in wild birds is through control and eradication of the virus in domestic poultry, especially in domestic ducks.