title: The Brucella abortus RB51 vaccine does not confer protection against Brucella ovis in rams.
abstract: The protective efficacy against Brucella ovis of the live vaccine Brucella abortus strain RB51 has been evaluated in rams using the attenuated B. melitensis strain Rev 1 as a reference vaccine. Sixteen Brucella-free rams, 6 months of age, were vaccinated subcutaneously with 4.18 x 10(10) c.f.u. RB51. Sixteen rams of the same condition and age were vaccinated subcutaneously the same day with 1.1 x 10(9) c.f.u. Rev 1. Fifteen similar rams were kept unvaccinated as controls. Six months after vaccination all rams were challenged with 3 x 10(9) c.f.u. B. ovis and slaughtered 8 weeks thereafter for bacteriological and pathological studies. The percentage of rams that were found infected was 68% (Rev 1), 100% (RB51) and 100% (controls). At necropsy, the percentage of organs found to be infected was significantly lower (p < 0.0005) in Rev 1-vaccinated (34%) than in RB51-vaccinated rams (74%) or controls (69%). In conclusion, the RB51 vaccine did not confer protective immunity against B. ovis in rams.
authors.affiliation: Dpt. Sanidad Animal, SIA/DGA, Zaragoza, Spain.
authors.forename: M P
authors.initials: MP
authors.lastname: Jiménez de Bagüés
authors.forename: M
authors.initials: M
authors.lastname: Barberán
authors.forename: C M
authors.initials: CM
authors.lastname: Marín
authors.forename: J M
authors.initials: JM
authors.lastname: Blasco
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000097:blood; D002004:Brucella Vaccine / Q000276:immunology; D002003:Brucella abortus / Q000276:immunology*; D002006:Brucellosis / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D007113:Immunity, Innate / Q000276:immunology; D008297:Male; D011897:Random Allocation; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology* / Q000517:prevention & control*
chemical_list: D000907:Antibodies, Bacterial; D002004:Brucella Vaccine