腮腺炎减毒活疫苗工作代毒种工艺优化

Optimization of preparation process for working virus seeds of live attenuated mumps vaccine

目的优化腮腺炎毒种制备工艺,控制麻腮风联合减毒活疫苗(measles,mumps and rubella combined vaccine,live,MMR)中腮腺炎分型基础滴度和稳定性。方法应用全自动细胞计数仪提高鸡胚活细胞计数精度,确定MOI并按最适MOI制备腮腺炎病毒工作种子批,选取病毒最适收获时间,优化腮腺炎病毒工作种子批制备工艺。采用优化后的毒种连续制备3批次腮腺炎病毒原液,检测原液病毒滴度及由其制备的MMR中腮腺炎病毒分型基础滴度与(37±1)℃1周热稳定性。结果优化后的毒种制备的腮腺炎病毒原液滴度稳定在6.5～7.0 lg CCID_(50)/m L,较优化前提高了0.5～0.7个log。采用优化后腮腺炎病毒原液制备的MMR中的腮腺炎病毒分型基础滴度在5.2～5.8 lg CCID_(50)/m L,热稳定性在4.8～5.5 lg CCID_(50)/m L;80%的MMR中麻腮风各组分病毒比均能达到1∶>20∶1。结论优化后的腮腺炎病毒工作种子批制备的MMR中腮腺炎病毒分型基础滴度和稳定性均显著提升。

Objective To control the basal titer and stability of mumps virus in live attenuated measles, mumps and rubella （MMR） combined vaccine by optimizing the preparation process of the mumps virus working seeds. Methods Fully-automated cell counter was used to improve the precision of chick-embryo cell counting. MOI was determined and the mumps working seed lot was prepared at the optimal MOI. The harvest time was optimized by plotting the complete virus growth curve to optimize the preparation process of the mumps virus working seed lot. Three consecutive batches of mumps virus bulk were prepared with the optimized virus seeds and determined for titer, with which the prepared live attenuated MMR combined vaccine were determined for basal titer of mumps virus as well as the titer after storage at （37 ±1 ）℃ for 7 d. Results The titer of mumps virus bulk prepared with the optimized virus seeds was in the range of 6. 5 - 7. 0 lgCCIDs0/mL, which was 0. 5 - 0. 7 log higher than that prepared with the virus seeds before optimi- zation. However, the basal titer of mumps virus in MMR prepared with the optimized bulk was 5.2 - 5. 8 lgCCIDso/mL, while that after storage at （37 ±1） ℃ for 7 d was 4. 8 - 5.5 lgCCIDso/mL. The ratios of measles virus：mumps virus ： rubella virus in 80% of MMR combined vaccine reached 1 ： 〉 20 ： 1. Conclusion Both the basal titer and stability of mumps virus in MMR combined vaccine prepared with the optimized working seeds of mumps virus were improved significantly.