title: Safety and efficacy of reduced doses of Brucella melitensis strain Rev. 1 vaccine in pregnant Iranian fat-tailed ewes.
abstract: Brucellosis is one of the most important zoonotic diseases and is a significant cause of abortion in animals. Brucella melitensis strain Rev. 1 is recommended as the most effective vaccine for small ruminants but the application of full doses in adult animals is restricted. This study was conducted to determine a proper reduced dose of vaccine which confers protection but which is not abortifacient in Iranian fat-tailed sheep. A total of 51 non-vaccinated pregnant ewes were divided into three main groups and several subgroups. Ewes in different groups were vaccinated at different stages of pregnancy and various subgroups were subcutaneously immunised with different quantities of the micro-organism (7.5 × 10(6), 10(6), 5 × 10(5)). Ewes again became pregnant a year later and were challenged with the wild-type strain to evaluate the protection conferred. Results revealed that the proportion of vaccination-induced abortions was significantly higher in ewes immunised with 7.5 × 10(6) Rev. 1 organisms than in those which received 10(6) or 5 × 10(5) bacteria. While 80% of non-vaccinated ewes aborted after challenge, none of the vaccinated ewes aborted post-challenge. This study indicated that a reduced dose of Rev. 1 vaccine containing 10(6) or 5 × 10(5) live cells could be safely used to induce protection in Iranian fat-tailed sheep at various stages of pregnancy.
authors.affiliation: Department of Veterinary Vaccine Release, Razi Vaccine and Serum Research Institute, 3197619751 Karaj, Iran. mebrahimi646@yahoo.com
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ebrahimi
authors.forename: Ramin Bagheri
authors.initials: RB
authors.lastname: Nejad
authors.forename: Saeed
authors.initials: S
authors.lastname: Alamian
authors.forename: Ladan
authors.initials: L
authors.lastname: Mokhberalsafa
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Abedini
authors.forename: Rainak
authors.initials: R
authors.lastname: Ghaderi
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Jalali
mesh_terms: D000818:Animals; D001428:Bacterial Vaccines / Q000008:administration & dosage* / Q000009:adverse effects; D002006:Brucellosis / Q000517:prevention & control / Q000662:veterinary*; D005260:Female; D007492:Iran; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000517:prevention & control / Q000662:veterinary*; D012756:Sheep; D012757:Sheep Diseases / Q000517:prevention & control*
chemical_list: D001428:Bacterial Vaccines; C471349:Rev.1 vaccine, Brucella melitensis