Blasco J M
Dpt. Sanidad Animal, SIA/DGA, Zaragoza, Spain.
Prev Vet Med. 1997 Aug;31(3-4):275-83. doi: 10.1016/s0167-5877(96)01110-5.
The live Brucella melitensis Rev 1 strain is considered the best vaccine available for the prophylaxis of brucellosis in small ruminants. The classically recommended exclusive vaccination of young replacement animals has failed to control brucellosis in some developed countries and is frequently inapplicable in the developing world. Accordingly, whole-flock vaccination is the only feasible alternative to control B. melitensis infection in small ruminants under the extensive management conditions characteristic of these countries. This review describes the practical problems encountered and the experience acquired over the past decade (particularly in Spain) using the Rev 1 based control strategy. The vaccination of pregnant animals with full standard doses of Rev 1 administered subcutaneously is followed by abortion in most vaccinated animals. Reducing the dose of vaccine has been suggested as a method of avoiding this problem and, accordingly, a reduced-dose vaccination strategy has been widely used and has been reported as a safe and effective method of controlling small ruminant brucellosis. However, we reviewed field and experimental results supporting the fact that as a result of the induction of abortion in pregnant animals and the low degree of immunity conferred, reduced doses of Rev 1 should not be recommended as an alternative to the full standard doses. When tested in a mouse model, differences in residual virulence and immunogenicity have been demonstrated between the different Rev 1 vaccines produced world-wide. These differences could account for the discrepancies in safety results obtained in mass vaccination trials in different countries. The induction of abortions when vaccinating pregnant animals means that there is no entirely safe strategy for Rev 1 vaccination. Conjunctival vaccination is safer than subcutaneous vaccination but is not safe enough to be applied regardless of the pregnancy status of the animals, and should be used only under restricted conditions. For sheep, conjunctival administration of standard doses of Rev 1 during the late lambing season or during lactation is recommended as a whole-flock vaccination strategy.
布鲁氏菌 melitensis Rev 1 活菌株被认为是预防小反刍兽疫布鲁氏菌病的最佳可用疫苗。传统上推荐对年轻的后备动物进行独家疫苗接种，但在一些发达国家未能控制布鲁氏菌病，并且在发展中国家通常不适用。因此，在这些国家广泛管理条件下，全群疫苗接种是控制小反刍兽疫布鲁氏菌感染的唯一可行选择。本综述描述了过去十年（特别是在西班牙）使用基于 Rev 1 的控制策略时遇到的实际问题和获得的经验。大多数接种皮下全标准剂量 Rev 1 的怀孕动物在接种后会流产。有人建议减少疫苗剂量以避免这个问题，因此，减少剂量的疫苗接种策略已被广泛使用，并被报道为控制小反刍兽疫布鲁氏菌病的安全有效方法。然而，我们回顾了支持以下事实的现场和实验结果：由于怀孕动物流产的诱导以及所赋予的低免疫程度，不应推荐使用减少剂量的 Rev 1 作为全标准剂量的替代方案。在小鼠模型中进行测试时，已证明全球生产的不同 Rev 1 疫苗在残余毒力和免疫原性方面存在差异。这些差异可以解释在不同国家的大规模疫苗接种试验中获得的安全结果的差异。给怀孕动物接种疫苗时导致流产意味着 Rev 1 疫苗接种没有完全安全的策略。结膜接种比皮下接种更安全，但无论动物的怀孕状态如何都不够安全，不能应用，应仅在受限条件下使用。对于绵羊，建议在产羔后期或哺乳期结膜接种标准剂量的 Rev 1 作为全群疫苗接种策略。
