表达ILTV gB和UL32基因的重组鸡痘病毒疫苗安全性及稳定性分析

Safety and Stability Evaluation of Recombinant Fowlpox Virus Expressing UL32 Gene and g B gene of Infectious Laryngotracheitis Virus

将重组疫苗在SPF鸡中进行连续传代评估表达ILTV g B和UL32基因的重组鸡痘病毒疫苗的安全性及稳定性。研究结果显示,将重组疫苗在SPF鸡体内连传5代,未观察到接种鸡有不良反应。接种鸡仅短暂排毒且重组病毒在环境中存在时间极短,而同居非免疫鸡未被感染,表明重组病毒不具有水平传播能力。免疫后14 d对第1代和第5代接种鸡进行鸡痘强毒株攻击,保护率均在90%以上,表明重组疫苗具有较好的保护力。第5代病毒与第1代病毒相比,UL32基因的序列无任何变异,表明该疫苗具有良好的遗传稳定性,且各代次毒株毒价稳定,无毒力返强现象。以上结果显示,表达ILTV g B和UL32基因的重组鸡痘病毒疫苗具有良好安全性和稳定性。

To evaluate the safety and stability of recombinant fowlpox virus （rFPV）with UL32 and gB gene of infectious laryngo- tracheitis virus （ILTV）, the recombinant vaccine was passaged in SPF chickens. Our results showed that there was not any adverse re- action in the vaccinated chickens. The remained time of rFPV in the environment was very short and the non-immunized chickens were not infected in the same condition, indicating the free of horizontal transmission of rFPV. 14 days after vaccination, the first and fifth generation of chickens were both challenged with vFPV and the protection rate was above 90% ,which suggested the recombinant vaccine could induce good immune protection to body. Compared with the first generation, the UL32 gene of the fifth generation didn＇ t show any mutation through five passages in SPF chicken, which suggested the genetic stability of rFPV. The virus titer was constant in all generations. All these results above indicated the safety and genetic stability of Recombinant Fowipox virus.