title: Efficacy of vaccination for bluetongue virus serotype 8 performed shortly before challenge and implications for animal trade.
abstract: Vaccination is the most effective strategy for controlling Bluetongue virus (BTV) spread and economic consequences thereof. In this study we verified in sheep, using one commercially available inactivated vaccine for BTV-8 (BTVPUR AlSap 8), when, during the recommended vaccination schedule, animals start to be effectively protected against challenge with wild-type strain. To this aim, sheep were challenged at different time points shortly after the first vaccine injection. Twenty-four Sarda sheep were divided into four groups vaccinated two weeks before challenge (Group A), one week before challenge (Group B) and concurrently with challenge (Group C). A second vaccine was performed twenty-eight days later with respect the first vaccine administration in each experimental group. The last group consisted of six non vaccinated-infected animals (NVIA). Virological and serological examinations were performed before and after challenge up to 42 and 77days post challenge, respectively. The results of the study show that vaccination commenced as little as two weeks before challenge (Group A) prevented viremia and RNAemia in challenged sheep altogether. Conversely, Group B was partially protected from challenge and Group C showed viraemia and RNAemia similar to NVIA. This study indicates that the first administration of inactivated vaccine performed two weeks before challenge was able to prevent viraemia. Overall, our findings may have direct consequences for the management of an unexpected BTV-8 outbreak in sheep and for the legislation on sheep trade from BTV restriction areas.
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise (IZSAM), Campo Boario, 64100, Teramo, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Spedicato
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise (IZSAM), Campo Boario, 64100, Teramo, Italy. Electronic address: a.lorusso@izs.it.
authors.forename: Alessio
authors.initials: A
authors.lastname: Lorusso
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise (IZSAM), Campo Boario, 64100, Teramo, Italy.
authors.forename: Romolo
authors.initials: R
authors.lastname: Salini
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise (IZSAM), Campo Boario, 64100, Teramo, Italy.
authors.forename: Annapia Di
authors.initials: AD
authors.lastname: Gennaro
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise (IZSAM), Campo Boario, 64100, Teramo, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Leone
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise (IZSAM), Campo Boario, 64100, Teramo, Italy.
authors.forename: Liana
authors.initials: L
authors.lastname: Teodori
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise (IZSAM), Campo Boario, 64100, Teramo, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Casaccia
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise (IZSAM), Campo Boario, 64100, Teramo, Italy.
authors.forename: Ottavio
authors.initials: O
authors.lastname: Portanti
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise (IZSAM), Campo Boario, 64100, Teramo, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Calistri
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise (IZSAM), Campo Boario, 64100, Teramo, Italy.
authors.forename: Armando
authors.initials: A
authors.lastname: Giovannini
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise (IZSAM), Campo Boario, 64100, Teramo, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Savini
mesh_terms: D000818:Animals; D001819:Bluetongue / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D001820:Bluetongue virus / Q000276:immunology*; D065288:Serogroup; D012756:Sheep; D014611:Vaccination / Q000662:veterinary*; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*; D014766:Viremia / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology
chemical_list: D015164:Vaccines, Inactivated; D014765:Viral Vaccines
keywords: Animal trade; Bluetongue virus serotype 8; Emergency vaccination; Sheep; Vaccine