Selection And Optimization Of Thermo-stable Protectant For Lyophilized Infectious Bursal Disease(B87) Virus Vaccine

Infectious bursal disease(IBD)is an acute infectious disease caused by infectious bursal disease virus(IBDV)in chickens.The disease is mainly controlled by infectious bursal disease live vaccine.Most of the infectious bursal disease live vaccines are currently used in milk sugar as stabilizers.The stabilizers are simple and cheap to make but poor in heat-resistant protection,and need to be stored and transported at-15℃.In order to solve the defect of its poor heat stability,the uniform design method was adopted,designing different proportions of formulations to prepare the vaccine for heat-resistance test.Two samples of NO.4 and NO.7 with better heat-resistant stabilizers were selected.The vaccine with milk sugar stabilizers is the control group.Heat-resistant tests were carried out on NO.4,NO.7 and the control group stored for 7 and 14 days respectively at 37℃.The virus titer of No.4 decreased by0.19 and 0.25.The decline of No.7 was 0.13 and 0.32.The virus titerof the control group declined by 0.81 and 1.35.Heat-resistant tests were carried out on NO.4,NO.7 and the control group which were stored for 10 and 20 days respectively at 25℃.The decline of No.4 was 0.25 and 0.37,while the decline of No.7 was 0.17 and 0.38and the virus titer decline of the control group was 1.06 and 1.51.It shows a good heat-resistance effect.Preservation experiments were carried out on NO.4,NO.7 and the control group which were stored for 1 and 3 mouths at 4℃.The virus titer of No.4decreased by 0.05 and 0.05 while the virus titer decline of No.7 was 0 and 0.13.The virus titer decline of the control group was 0.06 and 0.18.According to the table of uniform design,the ingredients in the heat-resistant stabilizers of this uniform design are trehalose、mannitol、glucitol、pvp、glutamine and albumin.The above six kinds of ingredients are used in the heat-resistant stabilizers,and the titer losses of the samples that make up of No.4 and No.7 ratio are lower in hear resistance test,which has practical value.The results of this study show that the protective effects of heat-resistant stabilizers on infectious bursal disease virus antigen are better than those of traditional milk sugar stabilizers,and have a good prospect of application.