Wu Qi, Wang Weihua, Zhang Xuehua, Li Ding, Mei Mei
Institute of Veterinary Immunology & Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
GuoTai (Taizhou) Center of Technology Innovation for Veterinary Biologicals, Taizhou 225300, China.
Vaccines (Basel). 2024 Jul 28;12(8):849. doi: 10.3390/vaccines12080849.
The enormous effects of avian influenza on poultry production and the possible health risks to humans have drawn much attention to this disease. The H9N2 subtype of avian influenza virus is widely prevalent among poultry, posing a direct threat to humans through infection or by contributing internal genes to various zoonotic strains of avian influenza. Despite the widespread use of H9N2 subtype vaccines, outbreaks of the virus persist due to the rapid antigenic drift and shifts in the influenza virus. As a result, it is critical to develop a broader spectrum of H9N2 subtype avian influenza vaccines and evaluate their effectiveness. In this study, a recombinant baculovirus expressing the broad-spectrum HA protein was obtained via bioinformatics analysis and a baculovirus expression system (BES). This recombinant hemagglutinin (HA) protein displayed cross-reactivity to positive sera against several subbranch H9 subtype AIVs. An adjuvant and purified HA protein were then used to create an rHA vaccine candidate. Evaluation of the vaccine demonstrated that subcutaneous immunization of the neck with the rHA vaccine candidate stimulated a robust immune response, providing complete clinical protection against various H9N2 virus challenges. Additionally, virus shedding was more effectively inhibited by rHA than by the commercial vaccine. Thus, our findings illustrate the efficacy of the rHA vaccine candidate in shielding chickens against the H9N2 virus challenge, underscoring its potential as an alternative to conventional vaccines.
禽流感对家禽生产的巨大影响以及对人类可能存在的健康风险已引起人们对该疾病的高度关注。禽流感病毒的H9N2亚型在家禽中广泛流行，通过感染或为各种人畜共患禽流感毒株提供内部基因对人类构成直接威胁。尽管H9N2亚型疫苗被广泛使用，但由于流感病毒的快速抗原漂移和变异，该病毒的爆发仍持续存在。因此，开发更广泛的H9N2亚型禽流感疫苗并评估其有效性至关重要。在本研究中，通过生物信息学分析和杆状病毒表达系统（BES）获得了一种表达广谱血凝素（HA）蛋白的重组杆状病毒。这种重组血凝素（HA）蛋白对几种H9亚型禽流感病毒（AIVs）的阳性血清显示出交叉反应性。然后使用佐剂和纯化的HA蛋白制备了一种候选重组HA疫苗（rHA疫苗）。对该疫苗的评估表明，用候选rHA疫苗对鸡颈部进行皮下免疫可刺激强烈的免疫反应，为抵御各种H9N2病毒攻击提供完全的临床保护。此外，与商业疫苗相比，rHA更有效地抑制了病毒脱落。因此，我们的研究结果说明了候选rHA疫苗在保护鸡免受H9N2病毒攻击方面的有效性，突出了其作为传统疫苗替代品的潜力。
