H9N2亚型禽流感病毒抗原性变异的研究

Research on antigenic drift of H9N2 subtype avian influenza viruses

对1998—2002年间在河南省豫北地区分离到的5株H9N2亚型禽流感病毒的抗原性变异进行了研究。经HI试验、鸡胚中和试验、细胞中和试验及攻毒保护试验证明，5株H9N2亚型间已经发生了抗原性漂移。98A5和99S毒株间的保护力接近100％，HI试验、鸡胚中和试验、细胞中和试验的相关性均在0．74以上。表明2毒株间的抗原性相近；用00Y毒株攻击其他4株免疫的鸡，其保护率仅为60％～80％；而02Y株对除00Y株外的4株的免疫保护率分别为60％、75％、80％、100％，与分离年代呈负相关性，HI、鸡胚中和试验、细胞中和试验也取得类似结果，说明2000年后的毒株间已发生抗原性变异。

To elucidate the antigenic drift of H9N2 subtype avian influenza viruses （AIVs）, five isolated AIV strains from the north of Henan province during 1998——2002 years were compared and analysed by cross hemagglutinin inhibition test （HI）, cross neutralization test （NT） in the chicken embryo and chicken embryo primary kidney cell （CEK） and cross protection against challenge infection test. When challenged by 00Y strain, the chickens inoculated with vaccine of other virus during 1998--2002 years cuold be protected only 60%-80%, which was consistent with the results of HI and NT. When challenged by 02Y strains, the protection rate was 60%,75%,80%, 100% respectively, and showed a negative relationship with the length of time except 00Y, which was similar with HI and NT. The results revealed that antigenic drift of HgN2 subtype avian influenza viruses had occurred during 1998--2002 years.