目的  观察水痘-带状疱疹病毒（varicella-zoster virus，VZV）Oka疫苗株（V-Oka株）的传代稳定性，并与分离于水痘患者的野毒株进行序列比对。方法  将V-Oka株在人二倍体细胞MRC-5中连续传代培养至50代，提取32、34、38、42、46和50代V-Oka株及野毒株的DNA，对主要基因（ORF31、 ORF62、ORF68、R区）进行PCR扩增和测序，并进行序列比对。结果  与Genbank 中的V-Oka株序列相比，32代至50代V-Oka株的ORF31、ORF62、ORF68、R区序列稳定，并趋于减毒。未发现野毒株序列发生如同V-Oka株的独特变异。结论  连续传代培养至50代， V-Oka株的分子遗传学特性保持稳定。序列比对显示，水痘患者的致病毒株为野毒株，而非V-Oka株。

Objective  To observe the stability of varicella-zoster virus(VZV) Oka vaccine(V-Oka) strain during subculture, and align VZV sequences between V-Oka strain and wild-type strain from chickenpox patients. Methods   V-Oka strain was subcultured to the 50th passage on human diploid cell MRC-5. VZV DNAs were extracted from the 32nd, 34th, 38th, 42nd, 46th and 50th passages of V-Oka strains and wild-type strains. The major genes(ORF31,ORF62,ORF68 and repeat regions)of V-Oka strains and wild-type strains were amplified by PCR and sequenced. DNA sequences between V-Oka strains and wild-type strains were aligned. Results  In comparison with DNA sequences of V-Oka strain in GenBank, ORF31, ORF62 ,ORF68, repeat regions sequences of V-Oka strains from the 32nd passage to the 50th passage were stable and seemed to be more attenuated. Unique mutations as same as in V-Oka stains were not observed in wild-type strains. Conclusions  The molecular genetic characteristics of V-Oka strains are stable till the 50th passage. The results of sequence alignment show that pathogenic strains in chickenpox patients are wild-type strains, but not V-Oka strains.