Research On Immunity Persistence Of Immune-Regulating DNA Vaccine PVAX1.0-TA4-IL-2Against Eimeriatenella

For apply new veterinary drugs certificate, according to the agriculture transgenic Organisms safety management statute of china, the immunity persistence of pVAX1.0-TA4-IL-2DNA vaccine against E.tenella was analysised.1. Optimization of immunization doses of pVAX1.0-TA4-IL-2DNA vaccine against E.tenellaSix experimental groups i.e.2μg,10μg,25μg,50μg,100μg and200μg dose groups were designed and the challenged and unchallenged control groups were also designed. There were8groups in all, every group has35chickens. At the age of14days, experimental group were intramuscularly injected with the corresponding immunizing dose, a booster immunization was given by the same method at the age of21days, the control groups were intramuscularly injected with PBS. At the age of28days, the chickens were vaccinated with5×104sporulated oocysts of E.tenella by oral except the unchallenged group. Seven days later, all the chickens were slaughtered. Body-weight gain, oocysts per gramfeces (OPG), lesion score and ACIs of each group were calculated. The results illustrated that ACIs of six groups were166.64,190.2,194.42,173.00,126.69,124.14respectively and the optimal dose of the DNA vaccine was25μg.2. The stability of three batchs pVAX1.0-TA4-IL-2DNA vaccine against E.tenellaAt the age of14days, experimental group was intramuscularly immunized with25μg dose of three batchs DNA vaccine respectively, a booster immunization was given by the same method at the age of21days, the control group was intramuscularly injected with PBS. At the age of28days, the chickens were vaccinated with5×104sporulated oocysts of E.tenella by oral except the unchallenged group. Seven days later, all the chickens were slaughtered. Body-weight gain, oocysts per (OPG), lesion score, and ACIs of each groups were calculated. The results illustrated that ACI of three batchs pVAX1.0-TA4-IL-2DNA vaccine were187.52,191.57,185.22respectively, the stability of DNA vaccine is better.3. The immunity protection period of pVAX1.0-TA4-IL-2DNA vaccine against E.tenellaFive groups i.e. A, B, C, D, E were designed, they contain experimental group, the challenged and unchallenged control groups. At the age of14days, the chickens of experimental group were immunized with25μg, a booster immunization was given by the same method as the first immunization7days later. The control groups were intramuscul arly injected with PBS. The chickens were vaccinated with5×104sporulated oocysts of E.tenella at the age of56d,84d,112d,140d,168d respectively except unchallenged control groups. Seven days later, all the chickens were slaughtered. Body-weight gain, oocysts per gramfeces (OPG), lesion score, and ACI of each group were calculated. The results illustrated that ACIs of pVAX1.0-TA4-IL-2DNA vaccine were182.28,162.23,154.58,150.54,144.53, the immunity persistence of pVAX1.0-TA4-IL-2DNA vaccine against E.tenella can retain two months to three months.4. The antibody dynamics of the immuned chickenExperimental group and control group were designed, every group has35chickens. At the age of14days, the experimental group of chickens was immunized with25μg, a booster immunization was given by the same method as the first immunization7days later. The control groups were intramuscularly injected with PBS. Then, serum was collected every other week. The antibody dynamics of immunized chicken was detected at2weeks post-immunized and the peak of the antibody appeared on42day post-immunized, then fall-off after two months. This result was in accordance with the previous data reported.