Study On Vaccine Produced By CEF To Defend Infectious Bursal Disease

Infectious bursal disease(IBD)is a high tangent infectious diseasecaused by infectious bursal disease virus (IBDV).Chicken and turkey can beinfected by it. Many infected chicken die of it.The most important, apermanent harm to bursal of infected chicken can be caused by it.This willlead to immunosupression. And immunosupression is a serious harm tochicken.At present there is infectious bursal disease in many places.Both theinfection rate and the mortality are very high. Vaccine immunity is the mainmeans to deal with this disease. Attenuted and inactived vaccines play animportant part in prevention to this disease, but immunity loss is very common.One reason is that the productive conditions are different, some good, somebad, the other is that the users don't know the characters of the vaccineswell,and they can't use it in a correct program. In order to control IBD better,we produced a safer and more effective vaccine (HDS) produced by CEF, andto summarize a battery of immunary programs and methods throughexperiments. Part Ⅰ:The production of HDS.We made some studies on themanufacture of CEF. we digested the tissue of chicken embryo with enzymefor several different times.The results showed that twenty minutes are betterthan other times.After the cell growed well,we added the primary virus toit.Studies showed that adding 0.2ml primary virus to 10ml increment fluid wasgood.The titers of virus we got is high. The titers of vaccine came up to 1×108PFU/ml. Part Ⅱ:The experiment of the security and potency of HDS.After theexperiments we confirmed that the best dose of immunity is 5×105PFU perchicken. We immunized the chicken with 5×106 PFU per chicken,and thechicken didn't show obvious reaction.This proved that HDS is safe.The 3邵云龙:鸡传染性法氏囊病细胞活疫苗的研制immuned chicken can resist the attack of vvIBDV.The ELISA titers to IBDVcan come up to 9000. Comparison experiments showed that HDS was betterthan other vaccines. Part Ⅲ:The impact of maternal antibody Through examination we gotthe variational rule of maternal antibody.The results showed that the antibodyrised from 1 to 4 days after birth.The peak reached 4000.The antibody levelcame down from 7 to 18 days. After birth.From 18 to 25 days,the antibodycame down quickly.To the chicken with maternal antibody,we inoculated HDSat 4,7,10,14,18,21 days after birth.The exemination showed that theimmunity at 14 days after birth is better.