目的 研究乙型脑炎(乙脑)减毒活疫苗冻干稳定剂中各组分（蔗糖乳糖溶液、尿素、人血白蛋白、明胶）对病毒滴定方法（噬斑法）的影响，进一步确定该方法的专属性。方法 采用噬斑法对不同浓度的乙脑疫苗稳定剂各组分分别进行滴定，考察各组分对BHK₂₁细胞的影响。取3批乙脑疫苗原液与稳定剂各组分分别混合为实验组，与病毒稀释液混合为对照组，采用噬斑法检测实验组与对照组的病毒滴度并进行统计分析。结果 稳定剂中各组分对BHK₂₁细胞无影响。将乙脑病毒完全中和后，细胞板上没有噬斑形成。实验组与对照组病毒滴度差异无统计学意义，t值分别为蔗糖乳糖溶液0.24，明胶-0.09，尿素-0.15，人血白蛋白-0.05，P值均大于0.05。结论 噬斑法检测乙脑病毒的专属性良好，可用于乙脑疫苗的病毒滴度检测。

Objective To investigate the possible effects of key components in the lyophilization stabilizer of live attenuated Japanese encephalitis vaccine (JEV), including lactose-sucrose solution, urea, human albumin and gelatin, on Japanese encephalitis virus titrimetry (plaque assay), to further confirm the specificity of the method. Methods Key components in lyophilization stabilizer of JEV at different concentrations were tested by plaque assay to investigate their effects on BHK₂₁ cells. Three batches of JEV bulk were mixed with each components as test groups, and with virus diluent as control group. Virus titers of all groups were tested by plaque assay and compared statistically. Results Key components in lyophilization stabilizer had no effect on BHK21 cells. After JEV bulk was completely neutralized, no plaque was formed on the cell plate. The t values between the mixtures of test and control were lactose-sucrose solution 0.24, gelatin -0.09, urea -0.15 and human albumin -0.05, with P values all ＞0.05, which showed no statistical significance. Conclusion Japanese encephalitis virus titrimetry by plaque assay has good specificity, and can be used for titrimetry of live attenuated JEV.