title: Efficacy assessment of an MVA vectored Rift Valley Fever vaccine in lambs.
abstract: The present study has evaluated the protection conferred by a single subcutaneous dose of a modified vaccinia virus Ankara (MVA) vectored vaccine encoding the Rift Valley Fever virus (RVFV) glycoproteins Gn and Gc in lambs. Three groups of six to seven lambs were immunized as follows: one group received the vaccine (termed rMVA-GnGc), a second group received an MVA vector (vector control) and a third group received saline solution (non-vaccinated control). Fourteen days later, all animals were subcutaneously challenged with 10(5) TCID50 of the virulent RVFV isolate 56/74 and vaccine efficacy assessed using standard endpoints. Two lambs (one from the vaccine group and one from the vector control group) succumbed to RVFV challenge, showing characteristic liver lesions. Lambs from both the vector control and non-vaccinated groups were febrile from days 2 to 5 post challenge (pc) while those in the rMVA-GnGc group showed a single peak of pyrexia at day 3 pc. RVFV RNA was detected in both nasal and oral swabs from days 3 to 7 pc in some lambs from the vector control and non-vaccinated groups, but no viral shedding could be detected in the surviving lambs vaccinated with rMVA-GnGc. Together, the data suggest that a single dose of the rMVA-GnGc vaccine may be sufficient to reduce RVFV shedding and duration of viremia but does not provide sterile immunity nor protection from disease. Further optimization of this vaccine approach in lambs is warranted.
authors.affiliation: Centre de Recerca en Sanitat Animal, CReSA, UAB-IRTA, 08193 Barcelona, Spain.
authors.forename: Núria
authors.initials: N
authors.lastname: Busquets
authors.affiliation: Centro de Investigación en Sanidad Animal, CISA-INIA, Valdeolmos, 28130 Madrid, Spain.
authors.forename: Gema
authors.initials: G
authors.lastname: Lorenzo
authors.affiliation: Centro de Investigación en Sanidad Animal, CISA-INIA, Valdeolmos, 28130 Madrid, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: López-Gil
authors.affiliation: Centre de Recerca en Sanitat Animal, CReSA, UAB-IRTA, 08193 Barcelona, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Rivas
authors.affiliation: Centre de Recerca en Sanitat Animal, CReSA, UAB-IRTA, 08193 Barcelona, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Solanes
authors.affiliation: Departament de Sanitat i d'Anatomia Animals, Universidad Autónoma de Barcelona (UAB), 08193 Barcelona, Spain; WorldPathol S.L., 50018 Zaragoza, Spain.
authors.forename: Iván
authors.initials: I
authors.lastname: Galindo-Cardiel
authors.affiliation: Centre de Recerca en Sanitat Animal, CReSA, UAB-IRTA, 08193 Barcelona, Spain.
authors.forename: F Xavier
authors.initials: FX
authors.lastname: Abad
authors.affiliation: Centre de Recerca en Sanitat Animal, CReSA, UAB-IRTA, 08193 Barcelona, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Rodríguez
authors.affiliation: Centre de Recerca en Sanitat Animal, CReSA, UAB-IRTA, 08193 Barcelona, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Bensaid
authors.affiliation: The Jenner Institute, University of Oxford, OX3 7DQ Oxford, United Kingdom.
authors.forename: George
authors.initials: G
authors.lastname: Warimwe
authors.affiliation: The Jenner Institute, University of Oxford, OX3 7DQ Oxford, United Kingdom.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Gilbert
authors.affiliation: Centre de Recerca en Sanitat Animal, CReSA, UAB-IRTA, 08193 Barcelona, Spain; Departament de Sanitat i d'Anatomia Animals, Universidad Autónoma de Barcelona (UAB), 08193 Barcelona, Spain.
authors.forename: Mariano
authors.initials: M
authors.lastname: Domingo
authors.affiliation: Centro de Investigación en Sanidad Animal, CISA-INIA, Valdeolmos, 28130 Madrid, Spain. Electronic address: brun@inia.es.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Brun
mesh_terms: D000818:Animals; D004337:Drug Carriers; D005260:Female; D005334:Fever / Q000209:etiology; D005822:Genetic Vectors; D007279:Injections, Subcutaneous; D008099:Liver / Q000473:pathology; D008297:Male; D009055:Mouth / Q000821:virology; D009296:Nasal Cavity / Q000821:virology; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D012295:Rift Valley Fever / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D012296:Rift Valley fever virus / Q000235:genetics / Q000276:immunology*; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D016019:Survival Analysis; D016896:Treatment Outcome; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014616:Vaccinia virus / Q000235:genetics*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D017201:Virus Shedding
chemical_list: D004337:Drug Carriers; D012367:RNA, Viral; D014614:Vaccines, Synthetic; D014765:Viral Vaccines
keywords: GnGc glycoproteins; MVA vaccine; Rift Valley Fever virus; Sheep experimental infection; Virus shedding