2005年浙江麻疹流行株与疫苗株基因组比较分析

Comparative analysis of measles genome between vaccine strain and wild-type strain in Zhejiang province of China

目的通过对麻疹暴发疫情中分离的麻疹流行株MVi／Zhejiang．CHN／7．05／4与麻疹疫苗株沪191全基因组比较，分析当代麻疹流行株与疫苗株的基因差异。方法通过测定从2005年浙江省麻疹暴发疫情中分离到的麻疹流行株MVi／Zhejiang．CHN／7．05／4的全基因组序列，采用MEGA3．1软件对流行株与疫苗株的全基因组序列进行比对和分析，并结合流行病学资料对毒株的变异进行分析。结果流行株与疫苗株相比全基因组共发生822个碱基突变（变异率为5．17％），含161个异义突变，其中有3个变异位点导致了病毒糖基化位点的变异；用毒株制备抗血清进行交叉中和试验，流行株与疫苗株抗原比相差5．66倍。结论浙江省2005年麻疹暴发疫情分离的流行株MVi／Zhejiang．CHN／7．05／4和中国现行使用的麻疹疫苗株沪191在全基因组层面已存在一定的差异，疫苗对免疫人群的保护作用需做进一步追踪探讨。

Objective To explore the distinction between wild-type strain MVi/Zhejiang, CHN/ 7.05/4 and vaccine strain Shanghai-191 at genome level. Methods After sequencing of measles wild-stain MVi/Zhejiang. CHN/7.05/4, the distinction between the wild-type strain and the vaccine strain was analysed by MEGA 3.1 software at genome level, and the antigen variation was studied by means of combining the epidemiological data. Results There were 822 nucleotide differences （5.17%） and 161 amino acid differences between these two strains, including three glycosylation sites variation found. Meanwhile, the antigen ratio between wild-type strain and vaccine strain was found to be 5.66. Conclusion There should be certain differences between the contemporary wild-type strain MVi/Zhejiang, CHN/7.05/4 and vaccine strain Shanghai-191 at genome level, and the protective effects of measles vaccine should be studied further.