Study On Cloning And Purification And Inactivated Vaccine Of Bovine Foot-And-Mouth Disease Virus Type Asia Ⅰ

Foot-and-mouth of disease(FMD) have broken out five times in China since 1999. Up to now,the epidemic has not been controlled effectively,FMD epidemic have spread out and become prevailing in some regions,Due to the single type strain and the relatively simple and backward production technology,the current FMD vaccine immunity effective was low and its side reaction was obvious.The vaccine prophylactic against FMD was in a low level.It has become necessary and urgent to clone and purify virus and develop inactivated vaccine by improving production process and the purity of antigen,the study contents are as follow:1.Clone and re-clone Foot-and-mouth of disease virus(FMDV) Asia 1 AKT03 strain by plaque test with BHK21 cells,then determine and compare the TCID₅0 and LD₅₀ of the first,the second cloned strain.The results showed that FMDV Asia 1 AKT03 was successfully cloned by plaque test.The PFU of post-cloned FMDV Asia 1 AKT03(3.0×10⁷pfu/mL) increased by 4 times than the one of pre-cloned strain (7.2×10⁶pfu/mL).The TCID₅₀(5.5-6.5) and LD₅₀(7.78-8.43) of post cloned FMDV Asia 1 AKT03 strain was obviously higher than the pre-cloned strain respectively,as the LD₅₀(7.78-8.43) and TCID₅₀(5.5-6.5) of post cloned to the pre-cloned LD₅₀ (6.88-7.43)and TCID₅₀(4.37-5.75).Both of the cloned viral TCID₅₀ and LD₅₀ potency were obviously improved.That provided high-grade antigen for preparing the FMD vaccine.2.Oil emulsion inactivated vaccine of FMDV was prepared with Asia 1 AKT03 cloned strain of bovine FMDV.The physical character of the inactivated vaccine,sterility test,safety test,and the immune efficacy test had been systematically studied.The Oil emulsion inactivated vaccine of FMDV Asia 1 prepared by cloning strain was milk,stable, sloppy,sterile and safe.It was showed by the immune efficacy test that PD₅₀ of the vaccine prepared by cloning strain improved by 2.4 times than the normal vaccine.It was indicated that the immune efficacy was obviously better than the normal vaccine.