Thirty epizootics of high pathogenicity avian influenza (HPAI) or fowl plague have occurred in poultry and other birds in the world since influenza virus was discovered to be the etiological agent of the disease in 1955 [1]. The largest epizootic of the past 50 years was the H5N1 panzootic, which began in the Guangdong province of southern China in 1996 and has since spread to affect 63 countries, resulting in the death or culling of over 250 million poultry and wild birds. Twenty four epizootics were eradicated using a four-component stamping-out strategy that included education, biosecurity, rapid diagnostics and surveillance, and elimination of infected birds. However, the inability of the stamping-out strategy to eradicate H5N2 HPAI in Mexico and H7N3 HPAI in Pakistan during 1994?1995 challenged the dogma of immediate eradication being achievable under all national political structures, poultry production systems, economic conditions and HPAI outbreak situations using traditional eradication methods [2]. Therefore, Mexico and Pakistan initiated the use of a fifth control component, increasing resistance of poultry to HPAI viruses by vaccination, which had been used previously to control low pathogenicity avian influenza (AI) in the USA and Italy [3?6]. More recently, vaccines for HPAI control have been utilized in the Democratic People?s Republic of Korea against H7N7 HPAI (2005) and in 13 of the 63 countries affected with H5N1 HPAI (1996 to present) [2]. Although the H5N1 HPAI panzootic continues, the H5N2 Mexican, H7N3 Pakistani and H7N7 Korean HPAI epizootics have ended. The recent Chinese Taipei (H5N2; 2012) and South African (H5N2; 2011) epizootics are nearing eradication using stamping-out programs only. . . .
Over the next 5 years, the highest priority needs for improving vaccines and vaccination in H5N1 HPAI enzootic control programs include:
? Restructuring and modernization of veterinary services in order to develop, implement, monitor and revise poultry vaccination programs, . . .
? Improving national HPAI surveillance programs to determine geographic locations, poultry species and production sectors where the virus resides . . .
? Restructuring funding for H5N1 HPAI control so that sufficient funds are available to veterinary medicine and agricultural production systems to develop effective control and eradication programs that will prevent human infection and eliminate the virus, . . .
? Improving vaccination rates among domestic ducks, which are a large asymptomatic reservoir of H5N1 HPAI virus in Asia, . . .
? Developing new vaccine vector platforms for cost-effective vaccination of short-lived meat chickens that do not require catching and handling of individual birds . . .
? Continuing development of antigenically relevant, rg AI seed strains for use in inactivated vaccines as field viruses drift antigenically away from current AI vaccine seed strains, . . .
? Developing a more time-responsive vaccine licensing and registration process by the national veterinary biological authorities for replaceable ?vaccine cassettes?, which would allow vaccine seed strains to be updated more quickly.
