大流行流感疫苗毒种(NIBRG-14)的传代稳定性

Stability of Pandemic Influenza Vaccine Virus Strain NIBRG-14 during Subculture

目的观察大流行流感疫苗生产用毒种(NIBRG-14,E2代)的传代稳定性,为制定毒种传代限定次数提供依据。方法毒种通过SPF鸡胚传代,检测不同代次毒种的生物学指标,并对传代后的遗传稳定性指标,即关键基因(血凝素和神经氨酸酶)和其他基因进行测序分析。结果毒种经连续传代至E12代,各项生物学指标均保持良好的稳定性,E3～E12代病毒感染性滴度均不低于8.54lgEID50/ml,血凝滴度均不低于1∶256,E3、E4及E12代病毒间的HA基因序列均保持一致,基因中被删除的高致病区域的核苷酸序列保持稳定,NA等基因序列在传代过程中也保持一致。结论大流行流感疫苗生产用毒种(NIBRG-14,E2代)连续传10代(至E12代),其生物学和遗传稳定性良好。

Objective To observe the stability of pandemic influenza vaccine virus strain NIBRG-14 of passage E2 during subculture and provide a basis for determination of passage number limit of the candidate strain. Methods NIBRG-14 strain was subcultured in SPF embryonated eggs, and various passages were determined for biological indexes. The HA, NA and other genes of the strain after subculture were sequenced to evaluate the genetic stability. Results After NIBRG-14 strain was subcultured to passage E12, all the biological indexes showed good stability. The infectious titers of passages E3 - E12 were not less than 8.54 lgEID50/ ml, and the hemagglutination titers were not less than 1 ： 256. The HA gene sequences of passages E3, E4 and E12 were in agreement, in which the nucleotide sequences at highly pathogenic region deleted were stable. The NA gene sequence was also stable during subculture. Conclusion The virus strain NIBRG-14 used for production of pandemic influenza vaccine showed good biological and genetic stabilities during subculture for 10 passages （to passage E 12）.