Confer A W, Hall S M, Faulkner C B, Espe B H, Deyoe B L, Morton R J, Smith R A
Vet Microbiol. 1985 Dec;10(6):561-75. doi: 10.1016/0378-1135(85)90065-3.
Fifty-seven pregnant beef heifers that were unvaccinated or previously vaccinated with Brucella abortus S19, at a dose of either 10(9) or 10(10) colony-forming units (CFU), were challenge-exposed intraconjunctivally with virulent B. abortus S2308 at a dose of 9.4 X 10(6) CFU (Experiment 1) or 5.2 X 10(7) CFU (Experiment 2). In Experiment 1, S19 afforded significant protection (P less than 0.01) against challenge exposure in that 8 of 9 unvaccinated heifers, 1 of 11 vaccinated with 10(9) CFU, and 3 of 10 vaccinated with 10(10) CFU aborted or delivered weak, non-viable calves. In Experiment 2, vaccination did not afford significant protection (P greater than 0.05) in that 9 of 9 unvaccinated heifers, 8 of 10 vaccinated with 10(9) CFU, and 8 of 8 vaccinated with 10(10) CFU aborted. Serologic responses to B. abortus were determined by three standard tests, as well as a quantitative fluorometric immunoassay (FIAX) and an enzyme-linked immunosorbent assay. In Experiment 1, the early serologic response, 0-8 weeks after challenge, appeared greater for controls than for vaccinates, but in Experiment 2, the early response, 0-6 weeks after challenge exposure, appeared greater for vaccinates than for controls. The lymphocyte blast transformation assay, using heat-killed B. abortus as an antigen, was performed sequentially after challenge exposure. In general, mean responses were significantly higher (P less than 0.05) for vaccinated than for non-vaccinated heifers. For individual heifers, an association could not be established between the lymphocyte blast transformation assay and the clinical response to challenge exposure.
57头怀孕的肉用小母牛，要么未接种过疫苗，要么之前接种过流产布鲁氏菌S19，接种剂量为10⁹或10¹⁰菌落形成单位（CFU），通过结膜内接种剂量为9.4×10⁶CFU的强毒流产布鲁氏菌S2308进行攻毒（实验1）或5.2×10⁷CFU（实验2）。在实验1中，S19提供了显著的保护作用（P＜0.01）以抵御攻毒，因为9头未接种疫苗的小母牛中有8头、11头接种10⁹CFU的小母牛中有1头、10头接种10¹⁰CFU的小母牛中有3头流产或产下体弱、无法存活的犊牛。在实验2中，接种疫苗未提供显著的保护作用（P＞0.05），因为9头未接种疫苗的小母牛中有9头、10头接种10⁹CFU的小母牛中有8头、8头接种10¹⁰CFU的小母牛中有8头流产。通过三种标准检测以及定量荧光免疫测定法（FIAX）和酶联免疫吸附测定法来测定对流产布鲁氏菌的血清学反应。在实验1中，攻毒后0至8周的早期血清学反应，对照组似乎比接种疫苗组更大，但在实验2中，攻毒后0至6周的早期反应，接种疫苗组似乎比对照组更大。在攻毒后依次进行以热灭活的流产布鲁氏菌为抗原的淋巴细胞增殖转化试验。总体而言，接种疫苗的小母牛的平均反应显著高于未接种疫苗的小母牛（P＜0.05）。对于个体小母牛，淋巴细胞增殖转化试验与攻毒的临床反应之间无法建立关联。
