1988-2005年甲3亚型流感流行株与疫苗株的HA1区差异探讨

Study on the differences on HA1 regions between epidemic strains and vaccine strains of influenza virus subtype A3 from 1988 to 2005

目的从基因层面探讨18年来我国及欧美国家甲3亚型流感流行株与当时WHO疫苗推荐株之间的差异。方法收集1988-2005年间我国以及欧美国家的甲3亚型流感流行株与疫苗株的血凝素重链(HA1)区域的氨基酸序列,用BioEdit生物软件进行比较,分析其与当时疫苗推荐株在HA1以及HA1抗原决定簇区域的氨基酸差异。结果在HA1区以及HA1区抗原决定簇位点,我国甲3亚型流感流行株与当年疫苗株之间的差异,均大于它与下一轮疫苗株之间的差异,且已达到十分显著的程度(P<0．01)。而欧美国家甲3亚型流感流行株与当年疫苗株之间的差异,虽然稍大于它与下一轮疫苗株之间的差异,但尚不显著(P>0．05)。此外,使用多年的疫苗株,无论在我国还是欧美,随着疫苗使用年数的增加,流行株与疫苗株之间的差异不断增大。结论WHO推荐的甲3亚型疫苗株与我国甲3亚型流行株之间,从基因层面进行分析,存在明显的滞后现象。

Objective To study the differences between epidemic strains of influenza virus subtype A3 circulated in China and Occident in past 18 years, in genetic level, and vaccine strains recommended by WHO in corresponding time. Methods Amino acid sequences of HA1 regions of the epidemic strains, which circulated in China and Occident from 1988 to 2005, and the vaccine strains of influenza virus subtype A3 were compared by BioEdit and analyzed on the differences of HA1 and it＇s antigen determinants, Results Differences between epidemic strains and vaccine strains recommended in corresponding year, both in HA1 and it＇ s antigen determinant regions, were obviously greater than that between epidemic strains and vaccine strains recommended in next round （P〈 0.01）. However, differences between epidemic strains in Occident and vaccine strains recommended in corresponding year were slightly greater than that between epidemic strains and vaccine strains recommended in next round and it was not marked （P 〉0.05）. In addition, differences between epidemic strains and vaccine strains which being used for several years, whether in China or in Occident, constantly increased accompanying the used time prolonged. Conclusion There was an obvious lag between vaccine strains recommended by WHO, analyzed in genetic level, and epidemic strains of influenza virus subtype A3 circulated in China.