Biberstein E L, Riemann H P, Franti C E, Behymer D E, Ruppanner R, Bushnell R, Crenshaw G
Am J Vet Res. 1977 Feb;38(2):189-93.
A phase I formalin-inactivated Q fever vaccine, using the Nine Mile strain of the organism, was tested for its ability to prevent dairy cows from shedding Coxiella burnetti in their milk. More than 1,400 Holstein-Friesian dairy calves and heifers from 5 dairies were used in field trials lasting over a 3-year period. Vaccination of 476 calves resulted in a geometric mean antibody titer of 1:123.3 compared with 1:2.4 for 486 nonvaccinated calves. The milk samples from 163 vaccinated calves were tested by mouse inoculation after the cows commenced lactation and were placed in their respective milking herds. Of these vaccinated animals, only 2 cows (1%) from 1 herd were suspected shedders, but on subsequent testing gave negative results. Among 164 nonvaccinated (control) cows, 39 (24%) were shedding C burnetii in their milk; this figure corresponded to the prevalence (23%) of shedders in the general population of dairy cows in California. The results of the current field trials indicated that vaccination greatly reduced the shedding of the Q fever organism in the milk of dairy cows.
一种使用该生物体九英里菌株的I期福尔马林灭活Q热疫苗，对其预防奶牛在牛奶中排出伯氏考克斯体的能力进行了测试。来自5个奶牛场的1400多头荷斯坦-弗里生奶牛犊和小母牛用于持续3年多的田间试验。476头犊牛接种疫苗后的几何平均抗体滴度为1:123.3，而486头未接种疫苗的犊牛为1:2.4。163头接种疫苗的犊牛的奶牛开始泌乳并被放入各自的挤奶牛群后，通过小鼠接种对其牛奶样本进行了检测。在这些接种疫苗的动物中，只有来自1个牛群的2头奶牛（1%）被怀疑为排出者，但后续检测结果为阴性。在164头未接种疫苗（对照）的奶牛中，39头（24%）在牛奶中排出伯氏考克斯体；这一数字与加利福尼亚奶牛总体中排出者的患病率（23%）相符。当前田间试验的结果表明，接种疫苗大大减少了奶牛牛奶中Q热病原体的排出。
