Exotic and Emerging Avian Viral Diseases Research Unit, US National Poultry Research Center, Agricultural Research Service, US Department of Agriculture, Athens, GA, USA.
Methods Mol Biol. 2020;2123:211-225. doi: 10.1007/978-1-0716-0346-8_16.
Avian influenza (AI) vaccines for poultry are based on hemagglutinin (HA) proteins, and protection is specific to the subtype. An estimated 313 billion doses have been used between 2002 and 2018 for high pathogenicity AI control. No universal vaccines are currently available. The majority of AI vaccines are inactivated whole influenza viruses that are grown in embryonating chicken eggs, emulsified in oil adjuvant systems, and injected subcutaneously or intramuscularly. Live virus-vectored vaccines such as recombinant viruses of fowl pox, Newcastle disease, and herpesvirus of turkeys containing inserts of AI virus HA genes have been used on a more limited basis. Also, vaccines have been licensed or registered based on baculovirus and defective replicating alphavirus (RNA particles) expressing HA protein or DNA vaccine with HA gene insert. In studies to evaluate vaccine efficacy and potency, the protocol design and its implementation should address the biosafety level needed for the work, provide information required for approval by Institutional Biosafety and Animal Care Committees, contain information on seed strain selection, provide needed information on animal subjects and their relevant parameters, and address the selection and use of challenge viruses. Various metrics have been used to directly measure vaccine-induced protection, including prevention of death, clinical signs, and lesions; prevention of decreases in egg production and alterations in egg quality; quantification of the reduction in virus replication and shedding from the respiratory tract and gastrointestinal tracts; and prevention of contact transmission in in vivo poultry experiments. In addition, indirect measures of vaccine potency and protection have been developed and validated against the direct measures and include serological assays in vaccinated poultry and the assessment of the content of HA antigen in the vaccine. These indirect assessments of protection are useful in determining if vaccine batches have a consistent ability to protect. For adequate potency, vaccines should contain 50 mean protective doses of antigen per dose, which corresponds to 0.3-7.8 μg of HA protein in inactivated vaccines, depending on immunogenicity and antigenic relatedness of individual seed strains.
禽类流感（AI）疫苗基于血凝素（HA）蛋白，并且保护作用针对特定亚型。在 2002 年至 2018 年期间，估计已使用了 3130 亿剂用于高致病性 AI 控制。目前尚无通用疫苗。大多数 AI 疫苗是在鸡胚中生长的灭活全流感病毒，与油佐剂系统乳化，然后皮下或肌肉注射。基于重组禽痘病毒、新城疫病毒和火鸡疱疹病毒的活病毒载体疫苗已在更有限的基础上使用，这些病毒包含 AI 病毒 HA 基因的插入物。此外，基于杆状病毒和缺陷复制的甲病毒（RNA 颗粒）表达 HA 蛋白或具有 HA 基因插入物的 DNA 疫苗的疫苗已获得许可或注册。在评估疫苗效力和效力的研究中，方案设计及其实施应针对工作所需的生物安全水平，提供机构生物安全和动物护理委员会批准所需的信息，包含种子株选择信息，提供动物实验对象及其相关参数所需的信息，并解决挑战病毒的选择和使用问题。已经使用了各种指标来直接衡量疫苗诱导的保护作用，包括预防死亡、临床症状和病变；预防产蛋量下降和蛋品质改变；量化呼吸道和胃肠道中病毒复制和脱落的减少；以及预防体内禽类实验中的接触传播。此外，已经开发并验证了针对直接措施的疫苗效力和保护的间接措施，包括接种禽类中的血清学检测和疫苗中 HA 抗原含量的评估。这些保护的间接评估有助于确定疫苗批次是否具有一致的保护能力。为了获得足够的效力，疫苗每剂应含有 50 个平均保护剂量的抗原，这相当于灭活疫苗中 0.3-7.8μg 的 HA 蛋白，具体取决于各个种子株的免疫原性和抗原相关性。
