Boudaoud A, Alloui N
Département vétérinaire, Faculté des sciences, Université El-Hadj Lakhdar, Batna 5000, Algérie.
Rev Sci Tech. 2008 Dec;27(3):793-802.
The pathological and immunological effects of two infectious bursal disease (Gumboro disease) vaccines containing attenuated virus were evaluated under experimental conditions. A total of 200 conventional broiler chicks were divided into three batches, two of which were administered an experimental dose of Gumboro disease vaccine via the ocular route, at 14 days of age, using an 'intermediate' strain for one group and an 'intermediate plus' strain for the other. At different post-inoculation intervals, the chicks from the three batches were weighed and slaughtered and their bursa of Fabricius were removed to be weighed and subjected to histological examination. This allowed a lesion score and a ratio between the weight of the bursa of Fabricius and body weight to be calculated for each group of chicks. The immunosuppressive potential of the two vaccines was also estimated by evaluating the chicks' serological response to a Newcastle disease vaccine administered by eye-drop two weeks following vaccination against Gumboro disease. The results showed that the two vaccine strains were not of equal pathogenicity and that one was potentially immunosuppressive. The 'intermediate plus' strain proved to be more virulent than the 'intermediate' strain, as it caused greater atrophy and more severe lesions of the bursa of Fabricius. By exerting a more suppressive effect on the serological response of the chicks, the 'intermediate plus' vaccine also proved to be immunosuppressive. The three weeks of observation were not sufficient to ascertain whether the lesions caused by the two vaccines were temporary or whether the immunosuppressive state induced by the 'intermediate plus' strain was reversible.
在实验条件下评估了两种含减毒病毒的传染性法氏囊病（甘保罗病）疫苗的病理和免疫效果。总共200只常规肉鸡雏鸡被分成三组，其中两组在14日龄时通过眼内途径接种实验剂量的甘保罗病疫苗，一组使用“中等”毒株，另一组使用“中等加”毒株。在不同的接种后间隔时间，对三组雏鸡进行称重并宰杀，取出其法氏囊进行称重并进行组织学检查。这使得能够为每组雏鸡计算病变评分以及法氏囊重量与体重之间的比率。还通过评估雏鸡在接种甘保罗病疫苗两周后对通过滴眼接种的新城疫疫苗的血清学反应，来估计这两种疫苗的免疫抑制潜力。结果表明，两种疫苗毒株的致病性不相等，其中一种具有潜在的免疫抑制作用。“中等加”毒株比“中等”毒株的毒性更强，因为它导致法氏囊更大程度的萎缩和更严重的病变。通过对雏鸡的血清学反应产生更强的抑制作用，“中等加”疫苗也被证明具有免疫抑制作用。三周的观察不足以确定两种疫苗引起的病变是否是暂时的，或者“中等加”毒株诱导的免疫抑制状态是否可逆。
