重组鸡痘病毒首免与灭活疫苗加强免疫对高致病性禽流感免疫效果的影响

Effect of a vaccination strategy consisting of recombinant fowlpox virus prime and inactivated vaccine boost on protective efficacy against highly pathogenic avian influenza

用表达H5亚型禽流感病毒(AIV)HA与NA基因的重组鸡痘病毒(rFPV)rFPV-12LSH5NA对10日龄带有H5亚型AIV母源抗体的商品鸡进行了首次免疫,17日龄时再用H5亚型AIV全病毒灭活疫苗加强免疫。免疫鸡分为2个批次,分别在24和31日龄用H5亚型AIV进行致死性攻击。在24日龄攻毒组中,rFPV首免与全病毒灭活疫苗加强免疫组的死亡比例(0/17)显著低于17日龄全病毒灭活疫苗单独免疫组(16/17)。在31日龄攻毒组中,rFPV首免与全病毒灭活疫苗加强免疫组的死亡比例(0/17)显著低于10日龄rFPV单独免疫组(6/17)。结果显示,在鸡群普遍存在针对H5亚型AIV母源抗体的情况下,rFPV首免与全病毒灭活疫苗配合使用能使鸡体快速建立坚强的免疫保护反应,是一种非常有效的免疫策略。

Ten-day-old commercial chickens with maternal antibodies against H5 subtype avian influenza virus（AIV） were primarily vaccinated with a recombinant fowlpox virus（rFPV） rFPV-12LSH5NA expressing HA and NA genes of H5 subtype AIV strain G5,followed by a booster immunization with inacti- vated H5 subtype AIV vaccine on day-old 17. The 10-day-old chickens inoculated only with rFPV12LSH5NA and the 17-day-old chickens inoculated only with the inactivated vaccine were served as control groups. Chickens in all the groups were challenged intranasally with lethal doses of homologous H5 AIV on day-old 24 or 31. All chickens in the prime-boost group survived and the virus shedding rate was significantly reduced,compared to the groups with a single vaccination with the rFPV or the inactivated vaccine. These results indicated that the prime-boost strategy was very effective for protecting chickens against lethal challenge of high pathogenic avian influenza（HPAI） virus, even in the presence of maternal antibodies.