猪伪狂犬病基因缺失疫苗的制备、安全性、免疫原性、保存期测定及区域试验

The Preparation of Gene-deleted Vaccine against Swine Pseudorabies,Measurement of Its Safety,Immunogenicity,Shelf Life and the Evaluation of Vaccine by Field Trials

为了提供有效的伪狂犬病疫苗,用鸡胚成纤维细胞扩大培养了PrV HB-98突变株(TK-/gG-/LacZ+),研制了伪狂犬病基因缺失疫苗,并对该疫苗经肌肉接种、经口等免疫途径的最小免疫剂量进行了测定,同时也对4批疫苗的安全性、效力、免疫期和保存期进行了检测;同时将4批疫苗用于免疫23个猪场的母猪、新生仔猪和育肥猪进行区域试验。测定结果表明,疫苗经上述两种途径接种对不同阶段猪的最小免疫剂量均为105.0TCID50;10倍免疫剂量的疫苗对初生仔猪、15日龄仔猪和妊娠母猪是安全的,免疫猪能抵抗强毒的攻击;疫苗在4℃和-20℃下分别可保存6个月和12个月。对伪狂犬病毒抗体阴性的70日龄商品猪和种猪的免疫期为6个月。田间试验表明,4批猪伪狂犬病基因缺失疫苗安全有效,并可用于仔猪发病时的紧急接种。为猪伪狂犬病基因工程疫苗的制备与应用提供了有力的依据。

In order to provide the effective vaccine for the immunoprophylaxis of swine pseudorabies, a gene-deleted vaccine against pseudorabies was prepared using a previously constructed mutant, PrV HB-98 （TK^-/gG^-/Lac^Z＋ mutant）, that were grown with primary embryo fibroblast cells. The optimal doses for the oral and intramuscular administration of the vaccine were determined, and the safety, efficacy, immunoprotective duration and shelf life of the gene-negative vaccine were measured. In addition, the performances of four batches of the gene-negative vaccine were assessed through field trials, in which the vaccine was clinically applied to sows, piglets and growing pigs in 23 pig farms. The optimal doses of vaccine for oral and intramuscular administration for pigs at different stages were determined to be 10^5.0 TCID50. The vaccine was demonstrated to be safe to one-, fifteen-day old piglets and pregnant sows when it was used at dose of 106^6.0 TCID50, ten fold of the normal immune dose. The immunized pigs could be protected from challenge with the virulent PrV strain. The vaccine could be stored for six and twelve months under 4℃ and-20℃ respectively without fluctuation of performance. The immunoprotective duration could last for six months in PrV antibody-free commercial and breeding pigs. The highly safety and good efficacy of the vaccine were further confirmed by the results obtained from the field trials, and the vaccine could be used in PrV-suffered piglets to quickly cease the prevalence of Aujeszky＇s disease. In conclusion, the research provided the useful hints for vaccine production and field applications of the vaccine.