title: Efficacy of three candidate Rift Valley fever vaccines in sheep.
abstract: Rift Valley fever virus (RVFV) is a mosquito-transmitted Bunyavirus that causes high morbidity and mortality among ruminants and humans. The virus is endemic to the African continent and the Arabian Peninsula and continues to spread into new areas. The explosive nature of RVF outbreaks requires that vaccines provide swift protection after a single vaccination. We recently developed several candidate vaccines and here report their efficacy in lambs within three weeks after a single vaccination. The first vaccine comprises the purified ectodomain of the Gn structural glycoprotein formulated in a water-in-oil adjuvant. The second vaccine is based on a Newcastle disease virus-based vector that produces both RVFV structural glycoproteins Gn and Gc. The third vaccine comprises a recently developed nonspreading RVFV. The latter two vaccines were administered without adjuvant. The inactivated whole virus-based vaccine produced by Onderstepoort Biological Products was used as a positive control. Five out of six mock-vaccinated lambs developed high viremia and fever and one lamb succumbed to the challenge infection. A single vaccination with each vaccine resulted in a neutralizing antibody response within three weeks after vaccination and protected lambs from viremia, pyrexia and mortality.
authors.affiliation: Department of Virology, Central Veterinary Institute of Wageningen University and Research Centre, 8200 AB Lelystad, The Netherlands. jeroen.kortekaas@wur.nl
authors.forename: J
authors.initials: J
authors.lastname: Kortekaas
authors.forename: A F G
authors.initials: AF
authors.lastname: Antonis
authors.forename: J
authors.initials: J
authors.lastname: Kant
authors.forename: R P M
authors.initials: RP
authors.lastname: Vloet
authors.forename: A
authors.initials: A
authors.lastname: Vogel
authors.forename: N
authors.initials: N
authors.lastname: Oreshkova
authors.forename: S M
authors.initials: SM
authors.lastname: de Boer
authors.forename: B J
authors.initials: BJ
authors.lastname: Bosch
authors.forename: R J M
authors.initials: RJ
authors.lastname: Moormann
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D004195:Disease Models, Animal; D005334:Fever / Q000517:prevention & control; D012295:Rift Valley Fever / Q000276:immunology / Q000517:prevention & control*; D012296:Rift Valley fever virus / Q000276:immunology*; D012756:Sheep; D016019:Survival Analysis; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D014766:Viremia / Q000517:prevention & control
chemical_list: D000276:Adjuvants, Immunologic; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; D014765:Viral Vaccines