流行性乙型脑炎(乙脑)病毒是引起病毒性脑炎最主要的病毒之一,本文对我国分离株的表型和基因型特性进行了综合分析。生物学特征研究显示,不同毒株间存在空斑形态、小鼠神经侵入致病性、保护性抗原和血凝性的明显差异。中国在1977年前,自然界中仅存在基因Ⅲ型乙脑病毒,但自1977年以后基因Ⅰ型和Ⅲ型病毒均从自然界分离到,而基因Ⅰ型病毒已成为优势病毒,其中多数分离自蚊虫。基因序列分析显示,两种基因型的氨基酸序列差异率很小(≤3%),与当前广泛应用的减毒活疫苗株比较,仅≤3%的氨基酸序列差异率,这些差别主要存在于与SA14-14-2减毒相关的位点,提示SA14-14-2疫苗能够有效地保护这两种基因型毒株的感染。 Japanese encephalitis (JE) virus is one of the most important viruses that cause viral encephalitis. In this paper, the phenotypes and genotypes of isolates in our country were comprehensively analyzed. Biological characteristics of the study showed that there are plaque morphology between different strains of mice, the pathogenicity of nerve invasion, protective antigen and significant differences in hemagglutination. In China, only genotype III JEV exists in nature before 1977, but genotypes I and III have been isolated from nature since 1977, while genotype I viruses have become dominant viruses, the majority of which are isolated from mosquitoes . Gene sequence analysis showed that the amino acid sequence differences between the two genotypes were very small (≤3%). Compared with the currently widely used live attenuated vaccine strains, only <3% amino acid sequence variation rates were found, SA14-14-2 attenuated the relevant sites, suggesting that SA14-14-2 vaccine can effectively protect the infection of these two genotype strains.