7种血清4型禽腺病毒疫苗免疫效果比较

Evaluation of immune efficacy of seven serum type 4 fowl adenovirus vaccines

旨在评估不同类型血清4型禽腺病毒(FAdV-4)疫苗对鸡免疫保护效果,为养殖场选择合适疫苗提供参考。选取5个厂家生产的组织毒细胞毒混合疫苗、细胞毒疫苗和重组蛋白疫苗3种FAdV-4组分的7种疫苗进行评价,采用胸肌注射法免疫,每种疫苗免疫8只21日龄SPF鸡,并设攻毒对照组和空白对照组,在免疫后21 d采集血清测定中和抗体和Fiber-2抗体,同时用FAdV-4分离株进行攻毒,在攻毒后7 d采集肝脏、抗凝血和泄殖腔拭子检测FAdV-4,采集血清测定Fiber-2抗体。结果显示,在免疫后21 d,重组蛋白疫苗组产生的Fiber-2抗体水平显著高于其他组(P<0.05),但未产生中和抗体;组织毒细胞毒混合疫苗组和细胞毒疫苗组均产生不同水平中和抗体和Fiber-2抗体;细胞毒疫苗EV1组产生的中和抗体水平显著高于其他组(P<0.05),但同一厂家的细胞毒疫苗EV2组产生的Fiber-2抗体水平显著低于其他组(P<0.05);在攻毒后7 d,除重组蛋白疫苗BV组死亡1只外,其他各组均无死亡;重组蛋白疫苗组和细胞毒疫苗组出现少量排毒和心包积液;各组均产生高水平Fiber-2抗体。综上,不同抗原疫苗诱导产生中和抗体的能力不同,重组蛋白疫苗不能诱导产生中和抗体,其他2种抗原疫苗可诱导机体产生中和抗体,但相同工艺不同厂家疫苗(CV与BV、DV与EV1、EV2)、甚至相同工艺同一厂家的不同疫苗(EV1与EV2攻毒后的心包积液情况)免疫效果均存在差异。总体来看,疫苗免疫保护效果:组织毒细胞毒混合疫苗>重组蛋白疫苗>细胞毒疫苗,2种组织毒细胞毒混合疫苗AV1、AV2和重组蛋白疫苗CV均可有效预防FAdV-4感染。

This study was to evaluate the immune protective effect of different types of serum type 4 fowl adenovirus(FAdV-4)vaccines on chickens in order to provide reference for the selection of fowl adenovirus vaccines in breeding farms.Seven vaccines containing the tissue and cell derived FAdV-4,cell derived FAdV-4 and recombinant protein derived FAdV-4 produced by five manufacturers were chosen for efficacy evaluation.Each of the five vaccine products were used to immunize eight 21-day-old SPF chickens,respectively,by pectoral muscle injection,and the challenge control group and the blank control group were also set among the treated chickens.Serum samples were collected from the chickens at 21 days after the immunization for neutralizing antibodies and Fiber-2 antibodies.The immunized chickens were immediately challenged with FAdV-4 isolate,and samples of liver,anticoagulation and cloacal swabs were collected from these birds at 7 days after the challenge to determine FAdV-4 pathogens.Finally,serum samples were collected from them to detect Fiber-2 antibodies.The results showed that,at 21 days after the immunization,the level of Fiber-2 antibody produced in the recombinant protein FAdV-4 vaccine group was significantly(P<0.05)higher than that in the other groups,but no neutralizing antibody was produced in the chickens.Different levels of the neutralizing antibody and the Fiber-2 antibody were produced in both the tissue and cell derived FAdV-4 vaccine and cell derived FAdV-4 vaccine groups.The level of the neutralizing antibody produced by the cell derived FAdV-4 vaccine EV1 group was significantly(P<0.05)higher than that by the other groups,but the level of the Fiber-2 antibody produced by the EV2 group was significantly(P<O.05)lower than that by the other groups.At 7 days after the challenge,there was no death in all the groups except 1 death in the BV group.A small amount of virus release and hydropericardium were observed in the recombinant protein FAdV-4 vaccine group and the cell derived FAdV-4 vaccine group.High levels of the Fiber-2 antibody were produced in all the groups.The above results indicated that the abilities of different antigen vaccines to induce neutralizing antibodies were various.The recombinant protein FAdV-4 vaccine could not induce neutralizing antibodies,but the other two antigen vaccines could.However,the immune effects of the vaccines with the same process and by different manufacturers(CV and BV,DV and EV1,EV2),and even different vaccines with the same process and by same manufacturer(pericardial effusion after challenge with EV1 and EV2)were different.In general,the immunoprotective effects of the FAdV-4 vaccines were in the order of the tissue and cell derived FAdV-4 vaccine>the recombinant protein FAdV-4 vaccine>the cell derived FAdV-4 vaccine.Two tissue and cell derived FAdV-4 vaccines AV1 and AV2 produced and a recombinant protein FAdV-4 vaccine CV could effectively prevent FAdV-4 challenge.