不同鸡马立克病疫苗的免疫保护效果比较

Comparative Evaluation of Immunological Protective Efficacy Among Various Marek’s Disease Vaccines in Chickens

【目的】对国内外共7个批次/品种(A~D,F~H)的CVI988或CVI988+HVT商品疫苗进行免疫保护分析,以期了解不同马立克病(MD)疫苗的保护效果,为该病的防控提供参考。【方法】将140只1日龄SPF鸡随机分为9组,G01~G09组,其中G01~G07组(15只/组)分别按推荐剂量免疫A~D及F~H马立克病疫苗,G08(攻毒对照组,15只)和G09(空白对照组,20只)组不免疫,7日龄时G01~G08组分别经腹腔注射马立克病病毒(MDV)超强毒Md5株(1000 PFU/只),所有鸡隔离饲养120 d。通过检测疫苗毒蚀斑数、疫苗毒复制情况、攻毒后体重差异、临床表现和病理变化综合评估各疫苗的保护力。【结果】7个批次疫苗的病毒蚀斑数均符合国家标准(2000 PFU/羽份),疫苗F的病毒蚀斑数最高(6467 PFU/羽份)。以1羽份剂量免疫1日龄SPF鸡后,疫苗F的复制速率相对较快。用Md5株攻毒后,攻毒对照组鸡体重减轻,且有93.3%(14/15)的鸡死亡,100%(15/15)剖检出现MD典型病变;G01~G07各免疫组鸡体重与空白对照组鸡相比,均无显著差异(P>0.05),死亡比例分别为0/14、3/15、5/15、0/14、0/13、0/15和1/15,剖检出现MD典型病理变化的比例为5/14、8/15、7/15、5/14、3/13、3/15和5/15,攻毒保护试验结果显示,7个批次的马立克病疫苗对鸡均具有一定保护力,保护指数为45.7%~73.3%。【结论】不同厂家生产的鸡马立克病疫苗对MDV超强毒Md5株的攻击具有相似的保护效果,二价苗的保护力(73.3%)高于单价疫苗。

【Objective】To understand the immune protection effects of different commercial Marek’s disease vaccines,and provide valuable data for Marek’s disease prevention and control,this study analyzed the immune protection of 7 batches/varieties(A-D,F-H)of CV1988 or CVI988+HVT commercial vaccine.【Method】A total of 1401-day-old SPF chickens were randomly divided into 9 groups,groups G01 to G07.G01 to G07(15 chickens/group)were immunized with Marek’s disease vaccine A-D and F-H according to the manufacturer’s recommended dose,respectively,while groups G08(challenge control group,15 chickens)and G09(blank control group,20 chickens)were not immunized.At 7 days of age,the chickens of groups G01 to G08 were intraperitoneally injected with Md5 strain(1000 PFU/bird).All chickens were raised to 120 days of age.The protective effect of each vaccine was evaluated through the examination of virus plaque numbers,vaccine replication,weight differences post-challenge,clinical manifestations,and pathological changes.【Result】The virus plaque number of all 7 vaccine batches confirmed to national standard(2000 PFU/feather),and the virus plaque number of vaccine F(6467 PFU/feather)was the highest.The replication rate of vaccine F was faster than other vaccines.After challenged with Md5 strain,the weight of the challenge control group chickens were decreased,and the unvaccinated chickens challenged with Md5 had 93.3%(14/15)mortality,and 100%(15/15)MD lesions.Compared with blank control group,there was no significant difference in body weight in groups G01 to G07(P>0.05).The mortality of vaccinated chickens in groups G01-G07 were 0/14,3/15,5/15,0/14,0/13,0/15 and 1/15,respectively.The MD lesion proportion of vaccinated chickens in groups G01-G07 were 5/14,8/15,7/15,5/14,3/13,3/15 and 5/15,respectively.The results of immune challenge protection test showed that 7 batches of Marek’s disease vaccine had a certain protective effect on chickens,and the protection index of these vaccines were 45.7%-73.3%.【Conclusion】Different manufacturer’s Marek’s disease vaccine demonstrated comparable protective effect against Md5 strain of MDV.Furthermore,the bivalent vaccine exhibited higher protection(73.3%)compared to the monovalent vaccine.