Primary Research On Mice Model To Evaluate Immunity Efficiency Of FMD Inactivated Vaccine

【Objective】It is to establish an easy, good reproducibility and standardization method replacing the traditional animal protection test to evaluate FMD inactivated vaccine, this research plans to establish the mice model to evaluate the immunity efficiency of FMD inactivated vaccine.【Method】(1) Quantitated the 146S particle in viruses: After concentrating the viruses and then purifing it by means of sucrose density gradient centrifugation, the quantity of 146S particle was determined wih ultraviolet spectrophotometer and calculated by using the formulation. (2) Established the mice model: The BALB/c mice were immunized with three vaccines of No.060217 swine type O FMD inactivated vaccine (Ⅱ), No.060326 swine type O FMD inactivated vaccine (Ⅱ) , and No.060105 cattle and sheep type O, Asia-I FMD inactivated vaccine, respectively. The blood samples were collected from the vaccinated mice and the titer of anti-FMDV-specific neutralizing antibodies (NAb) were mensurated. The vaccinated mice were challenged with each homologic strain of vaccines respectively, as the mice immunized No.060217 vaccine with ON MF7, the mice immunized No.060326 vaccine with OZ MF9, the mice immunized No.060105 vaccine with ON MF7 and Asia-I MF15. The viremia in vaccinated mice were detected by suckingmice-infected test, and the mouse 50% protective doses (PD50) of the vaccines were calculated through the Reed-Muench method.【Result】(1)The quantity of 146S particle in viruses (inactivated vaccines): No.06026 viruses [No.060217 swine type O FMD inactivated vaccine (Ⅱ)] was 75.3ng/mL (75.3ng/dose), No.06041 viruses [No.060326 swine type O FMD inactivated vaccine (Ⅱ) ] was 75.7ng/mL (75.7ng/dose), the mixture of No.06001 and No.06005 viruses [No.060105 cattle and sheep type O, Asia-I FMD inactivated vaccine] was 61.2ng/mL (61.2ng/dose). (2)All mice immunized severally with No.060217, No. 060326 and No.060105 vaccines could product the NAb. The NAb titer were increasing along with the time and went to the max on the 28th day. The vaccinated mice were challenged singly with the vaccine homologic strains. The mouse PD50 were 3.55, 4.53, 3.09, 3.49 and the animal PD50 were 6.4, 6.4, 3.6, 5.4, respectively. There have some corresponding relationship between mice PD50 and animal PD50.【Conclusion】This research proves that the method by using the adult BALB/c mice challenge-protection trial and suckingmouse-infected test can evaluate the immunity efficiency of FMD inactivated vaccine.