Thornton D H
Dev Biol Stand. 1976;33:343-8.
A variety of criteria must be considered when examining the suitability of preparations of live infectious bursal disease (IBD) virus for use as vaccines: identity and purity of the vaccine strain, lack of spread, or of tendency to revert to virulence, lack of immunosuppressive effect, safety and potency. Arguments as to th identity of IBD virus are well documented, and after ensuring that the virus strain is in fact IBD virus, it must be ascertained that it is free from contaminating agents. If the vaccine strain spreads, lack of reversion to virulence must be determined by several direct chick to chick passages: histological observations of bursae from first and final passages must be made to ensure that no change has occurred. In order to formulate proposals for standard tests of safety, lack of immunosuppressive effect and potency for IBD vaccines, comparative studies were made of products of different origins. Safety of the vaccines was assessed by observing young chicks after administration and measuring loss in weight gain. The effect on the bursa was judged by weighing and making microscopic observations at intervals. The immunosuppressive effect of the vaccines was assessed by comparing the serological and protective responses to subsequent Newcastle disease (ND) vaccination with the response in chicks given no IBD vaccine. Potency of the vaccines was determined by challenge of vaccinated chicks with virulent IBD virus. Various properties were found in the products examined. Some were concluded to be insufficiently attenuated because of the effect on the bird or upon its bursa and the consequent effect on the bird's immune competence. The ability to confer protection was not correlated with the degree of damage caused in the bursa. Vaccines which had no adverse effect on the health of the bird, caused little or no damage to the bursa and conferred adequate protection against challenge were considered to be of a satisfactory standard.
在检查传染性法氏囊病（IBD）活病毒制剂作为疫苗使用的适用性时，必须考虑多种标准：疫苗株的同一性和纯度、无传播性或无返强倾向、无免疫抑制作用、安全性和效力。关于IBD病毒同一性的论据有充分记录，在确保病毒株确实是IBD病毒后，必须确定其无污染物。如果疫苗株传播，必须通过几次直接的鸡传鸡传代来确定无返强现象：必须对第一代和最后一代传代的法氏囊进行组织学观察，以确保没有发生变化。为了制定IBD疫苗安全性、无免疫抑制作用和效力的标准测试建议，对不同来源的产品进行了比较研究。通过观察给药后的幼鸡并测量体重增加的损失来评估疫苗的安全性。通过定期称重和显微镜观察来判断对法氏囊的影响。通过将对随后新城疫（ND）疫苗接种的血清学和保护性反应与未接种IBD疫苗的雏鸡的反应进行比较，来评估疫苗的免疫抑制作用。通过用强毒IBD病毒攻击接种疫苗后的雏鸡来确定疫苗的效力。在所检查的产品中发现了各种特性。一些产品由于对鸡或其法氏囊有影响，进而对鸡的免疫能力有影响，被认为减毒不足。赋予保护的能力与法氏囊中造成的损伤程度无关。对鸡的健康没有不良影响、对法氏囊造成很少或没有损伤并能提供足够的攻毒保护的疫苗被认为达到了令人满意的标准。
