| Two indirect-ELISA assays for detection and quantification of IgG antibody against fowl adenovirus groupâ… serum type 1 (FAV-1) in serum was standardized using the filtering method and sucrose gradient density centrifugal methods to prepare of FAV-1 as coating antigen.The optimum concentration of coating antigen respectively is 108.96copies/mL and 109.16copies/mL.The optimum diluted times both 1:100.The ELISA prepare by filtration method (filtration-ELISA) limit titer of FAV-1 positive control serum was 1:12800 and The ELISA prepare by sucrose gradient centrifugation method (SGC-ELISA) was 1:6400 respectively.The FAV-1 virion was highly special and had no cross-reactions with the positive sera of Avian influenza virus,New castle disease virus,Avian reovirus.The assays were highly reproducible with a less than 5% coefficient of variability percent (C.V%) in batch tests.Using two ELISA method also examined FAV-1 inactivated vaccine antibody level and clinical examination, the comparison results show that filtration-ELISA in the same antibody level ELISA OD value was higher 45.3% on average, at low levels of antibodies has higher detection sensitivity. Therefore,the two indirect-ELISA assays would provide a simple and rapid meas for monitoring FAV-1 infection and assessing vaccination in the field.An inactivated oil-emulsion vaccine was developed from fowl adenovirus group I serum type 1 (FAV-1). After optimization of virus replication condition, Determined the optimum inoculating dose is 105.4 TCID5o/mL and the optimum harvest time is 72-96h.Compared the inactived effect between formaldehyde and (3-propionolactone (BPL),The optimum using concentration of formaldehyde is 0.1% and the BPL is 0.05%。the virus with the titer of 10931 ELD50/mL.108.55 EID50/mL,108.14 TCID50/mL and concentration of 108.71copies/mL was used to prepare the vaccine.The developed vaccine with hydrophile-lipophile balance Number(HLB) 7.0, 10% emulsifier and oil-water ratio of 4:1 can provide stable immune protection. The Formulations inspection, stability testing,viscosity determination,asepsis inspection,safety inspection,storage life detection reached the required minimum requirements, and the minimum vaccine immune dose is 0.25 mLVaccined past two weeks begining the detection, the monitoring results of vaccine immune antibody level is that the antibodies level of immuned chicken group reached the OD450 value peak, and the antibody level slow start falling down after immuned 4 weeks。After immuned 8 weeks, the ELISA OD450 value is 0.731. The vaccined and challenge test confirm that the FAV-1 vaccine's protection ratio is 100% and against the attack from FAV-1 completely.The results of field animal experiments showed that the SPF chicken vaccined FAV-1 inactivated oil-emulsion vaccine antibody levels OD450 ELISA value is 1.103, reached the desired effect.The high antibody titer of 0.816 OD450 can be detect ed by ELISA from the SPF chicken vaccinated within four months, he antibody level slow start falling down after immuned five months and keeping the medium level in the vaccined past six mouth.The vaccine is safe and effective from chicken of different varieties and ages. |
