北京流感暴发流行前后流行株的分离和抗原性分析

目的：为获得1998年12月北京流感暴发前和后的流行株，并了解流行株的抗原变异幅度。方法：应用常规法进行流感病毒分离，应用血凝抑制免疫交叉试验（HI），以6株国际参考株和2株国家代表株，对流行株作抗原性分析。结果：共获甲3亚型（H3N2）流行株15株，它们的抗原性与A3／南非／1147／96、A3／悉尼／05／97、A3／日本／8／98、A3／智利／3792／98、A3／阿根廷／413／98均有明显差异。它们与国家代表株A3／山东／9／93的抗原性也有差异，但与A3／南昌／933／95和A3／汉防／359／95两株的抗原性无明显差异。结论：所分离到的15 均为甲3亚型流感毒株（H3N2），是北京1998年的流行优势株；同时也证实1998年12月北京流感暴发流行的病毒主要也是H3N2亚型毒株。它们的抗原性与国际参考株：南非、悉尼、日本、智利、阿根廷有明显差异。应用国际流感疫苗效果不佳的重要原因在于甲3亚型流行株与A3／悉尼／05／95国际代表株抗原性不大对应。

ISOLATION AND ANTIGENICITY ANALYSIS OF INFLUENZA EPIDEMIC STRAINS BEFORE AND AFTER THE PREVALENCE IN BEIJING

Objective:To obtain epidemic strains before and after the influenza prevalence in Beijing in Dec. 1998, and to understand the variation range of epidemic strains.Methods:Influenza viruses were isolatad by routine method and the antigenicities of epidemic strains were analyzed by using hemagglutinin inhibition(HI) cross test with six international strains and two national standard strains. Results:15 strains of H3N2 were got. Their antigenicities were obviously different from those of A3 international strains: A3/South Africa/1147/96,A3/Sydney/05/97,A3/Japan/8/98,A3/Chile/3792/98 and A3/Argentina/413/98. They were also different from that of national standard strain: A3/Shandong/9/93, but no significant difference from those of A3/Nanchang/933/95 and A3/Wuhan/359/95.Conclusion:H3N2 was the predominant epidemic strain in 1998,and was the main pathogen in the prevalence of influenza in Beijing in Dec. 1998. Their antigenicities were clearly distinct from international standard strains: South Africa, Sydney, Japan, Chile, and Argentin. Thus, the invalidation of international vaccine in China may result from poor antigen consistence between H3N2 epidemics and international strains such as A3/Sydney/05/95.