Srinivas G B, Walker A, Rippke B
Center for Veterinary Biologics, Animal and Plant Health Inspection Service, United States Department of Agriculture, P.O. Box 844, Ames, IA 50010, USA.
Biologicals. 2013 Sep;41(5):298-302. doi: 10.1016/j.biologicals.2013.06.005. Epub 2013 Jul 6.
Batch-release potency testing of leptospiral vaccines licensed by the United States Department of Agriculture (USDA) historically was conducted through animal vaccination-challenge models. The hamster vaccination-challenge assay was Codified in 1974 for bacterins containing Leptospira pomona, Leptospira icterohaemorrhagiae, and Leptospira canicola, and in 1975 for bacterins containing Leptospira grippotyphosa. In brief, 10 hamsters are vaccinated with a specified dilution of bacterin. After a holding period, the vaccinated hamsters, as well as nonvaccinated controls, are challenged with virulent Leptospira and observed for mortality. Eighty percent of vaccinated hamsters must survive in the face of a valid challenge. The high cost of the Codified tests, in terms of monetary expense and animal welfare, prompted the Center for Veterinary Biologics (CVB) to develop ELISA alternatives for them. Potency tests for other serogroups, such as Leptospira hardjo-bovis, that do not have Codified requirements for potency testing continue to be examined on a case-by-case basis.
美国农业部（USDA）许可的钩端螺旋体疫苗的批签发效价测试历来是通过动物接种-攻毒模型进行的。仓鼠接种-攻毒试验于1974年编入法典，用于含波摩那钩端螺旋体、出血性黄疸钩端螺旋体和犬型钩端螺旋体的菌苗，1975年编入法典用于含七日热钩端螺旋体的菌苗。简而言之，用特定稀释度的菌苗对10只仓鼠进行接种。经过一段饲养期后，对接种的仓鼠以及未接种的对照仓鼠用强毒钩端螺旋体进行攻毒，并观察死亡率。在有效的攻毒情况下，80%接种的仓鼠必须存活。从金钱成本和动物福利方面来看，编入法典的试验成本高昂，促使兽用生物制品中心（CVB）为其开发酶联免疫吸附测定（ELISA）替代方法。对于其他血清群，如没有效价测试编入法典要求的牛硬钩端螺旋体，效价测试仍在逐案审查中。
