Exotic and Emerging Avian Viral Diseases Research Unit, Southeast Poultry Research Laboratory, US National Poultry Research Center, Agricultural Research Service, US Department of Agriculture, 934, College Station Rd, Athens, GA 30605, United States.
Vaccine. 2017 Nov 1;35(46):6336-6344. doi: 10.1016/j.vaccine.2017.05.051. Epub 2017 May 26.
During December 2014-June 2015, the U.S. experienced a high pathogenicity avian influenza (HPAI) outbreak caused by clade 2.3.4.4 H5Nx Goose/Guangdong lineage viruses with devastating consequences for the poultry industry. Three vaccines, developed based on updating existing registered vaccines or currently licensed technologies, were evaluated for possible use: an inactivated reverse genetics H5N1 vaccine (rgH5N1) and an RNA particle vaccine (RP-H5), both containing the hemagglutinin gene of clade 2.3.4.4 strain, and a recombinant herpesvirus turkey vectored vaccine (rHVT-H5) containing the hemagglutinin gene of clade 2.2 strain. The efficacy of the three vaccines, alone or in combination, was assessed in White Leghorn chickens against clade 2.3.4.4 H5N2 HPAI virus challenge. In Study 1, single (rHVT-H5) and prime-boost (rHVT-H5+rgH5N1 or rHVT-H5+RP-H5) vaccination strategies protected chickens with high levels of protective immunity and significantly reduced virus shedding. In Study 2, single vaccination with either rgH5N1 or RP-H5 vaccines provided clinical protection in adult chickens and significantly reduced virus shedding. In Study 3, double rgH5N1 vaccination protected adult chickens from clinical signs and mortality when challenged 20weeks post-boost, with high levels of long-lasting protective immunity and significantly reduced virus shedding. These studies support the use of genetically related vaccines, possibly in combination with a broad protective priming vaccine, for emergency vaccination programs against clade 2.3.4.4 H5Nx HPAI virus in young and adult layer chickens.
2014 年 12 月至 2015 年 6 月期间，美国爆发了由 2.3.4.4 分支 H5Nx 鹅/广东系病毒引起的高致病性禽流感（HPAI），给家禽业带来了毁灭性的后果。三种疫苗被评估为可能的用途：一种基于更新现有注册疫苗或当前许可技术的灭活反向遗传学 H5N1 疫苗（rgH5N1）和一种 RNA 颗粒疫苗（RP-H5），均含有 2.3.4.4 分支的血凝素基因，以及一种含有 2.2 分支血凝素基因的重组疱疹病毒火鸡载体疫苗（rHVT-H5）。在白来航鸡中，单独或组合使用这三种疫苗对 2.3.4.4 分支 H5N2 HPAI 病毒进行了评估。在研究 1 中，单一（rHVT-H5）和初免-加强（rHVT-H5+rgH5N1 或 rHVT-H5+RP-H5）接种策略保护了鸡，使其获得高水平的保护免疫力，并显著减少了病毒脱落。在研究 2 中，单独接种 rgH5N1 或 RP-H5 疫苗可在成年鸡中提供临床保护，并显著减少病毒脱落。在研究 3 中，双 rgH5N1 疫苗接种可保护成年鸡免受临床症状和死亡率的影响，在加强后 20 周进行攻毒，具有高水平的持久保护免疫力，并显著减少病毒脱落。这些研究支持使用遗传相关疫苗，可能与广泛保护的初免疫苗联合使用，用于针对年轻和成年层鸡的 2.3.4.4 分支 H5Nx HPAI 病毒的紧急接种计划。
