Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea.
National Center for Veterinary Diagnostics, No. 11, 78th Lane, GiaiPhong Road, Dong Da, Hanoi, Viet Nam.
Vaccine. 2020 Jan 16;38(3):663-672. doi: 10.1016/j.vaccine.2019.10.044. Epub 2019 Oct 25.
The occurrence of severe outbreaks of highly pathogenic avian influenza in Korea led to establishment of a national antigen bank for emergency preparedness. Here, we developed five vaccines for this bank (clade 2.3.2.1C, clade 2.3.4.4A, B, C, and D) by reverse genetics, inactivated them with formalin, and evaluated the protective efficacy and potency of serial dilutions against lethal homologous challenge in specific-pathogen-free chickens. After vaccination with one dose, each vaccine resulted in 100% survival, with no clinical symptoms, or lack of detectable virus shedding, and high levels of pre-challenge protective immunity (8.4-10.2 log). After vaccination with one-tenth of the full dose, protection was similar to that with the full dose. After vaccination with one-hundredth of the initial dose, survival was 20-80%, and all vaccines showed virus shedding. Four vaccines (excluding clade 2.3.2.1C) had satisfactory potency. In antibody-persistence tests, all vaccines maintained long-lasting protective immunity. Our results suggest that inactivated reverse-genetics vaccines genetically matched to outbreak viruses provide adequate protection after a single vaccination.
韩国高致病性禽流感的严重爆发促使建立了国家抗原库以应对紧急情况。在这里，我们通过反向遗传学为该库开发了五种疫苗（2.3.2.1C 谱系、2.3.4.4A、B、C 和 D 谱系），用福尔马林将其灭活，并评估了针对特定病原体无鸡的同源致命性挑战的连续稀释的保护效力和效力。接种一剂后，每种疫苗均能 100%存活，无临床症状或无可检测到的病毒脱落，并且具有高水平的预先挑战保护免疫力（8.4-10.2 对数）。接种十分之一的全剂量后，保护作用与全剂量相似。接种初始剂量的百分之一后，存活率为 20-80%，所有疫苗均显示出病毒脱落。四种疫苗（不包括 2.3.2.1C 谱系）具有令人满意的效力。在抗体持久性测试中，所有疫苗均保持持久的保护免疫力。我们的结果表明，与暴发病毒基因匹配的灭活反向遗传学疫苗可在单次接种后提供充分的保护。
