title: Innocuity of a commercial live attenuated vaccine for epizootic hemorrhagic disease virus serotype 2 in late-term pregnant cows.
abstract: Epizootic hemorrhagic disease (EHD) is an arthropod-borne infectious viral disease sustained by the epizootic hemorrhagic disease virus (EHDV). The only commercially available and currently used vaccines are manufactured for EHDV-2 in Japan, either live or inactivated vaccines. In this study we tested the innocuity for fetuses of the live attenuated EHDV-2 vaccine in five late-term pregnant cows. Whole blood and serum samples were collected from dams and screened for the presence of EHDV-2 RNA, infectious virus and antibodies. After calving, whole blood and serum samples collected from calves, before and after colostrum intake, were also tested for antibodies and for virus detection. In dams, neither fever nor clinical signs were observed. All of them seroconverted and a strong humoral response was detected throughout the sampling period. All blood samples tested negative for EHDV-2 except for one sample collected from a dam 11 days post-vaccination which tested positive at virus isolation at the third cell passage following two rounds of blind passages. Although they had free access to colostrum, calves tested serologically negative for EHDV-2 during the entire course of the experiment. Overall, the tested live attenuated vaccine can be safely administered to late-term pregnant cows as it was not demonstrated to cross the placental barrier. The safety of the live-attenuated vaccine is further confirmed by the emergence of Ibaraki virus in 2013 in Japan which is apparently not related to the spread of the vaccine strain currently used in Japan.
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Teramo, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Spedicato
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Teramo, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Carmine
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Teramo, Italy.
authors.forename: Liana
authors.initials: L
authors.lastname: Teodori
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Teramo, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Leone
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Teramo, Italy.
authors.forename: Ottavio
authors.initials: O
authors.lastname: Portanti
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Teramo, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Marini
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Teramo, Italy.
authors.forename: Maura
authors.initials: M
authors.lastname: Pisciella
authors.affiliation: OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, 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 del Molise, Teramo, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Savini
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000821:virology; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control* / Q000821:virology; D005260:Female; D018164:Hemorrhagic Disease Virus, Epizootic; D010920:Placenta / Q000276:immunology; D011247:Pregnancy; D012367:RNA, Viral / Q000097:blood; D012088:Reoviridae Infections / Q000517:prevention & control / Q000662:veterinary*; D000069078:Seroconversion; D065288:Serogroup; D014613:Vaccines, Attenuated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*; D014766:Viremia / Q000175:diagnosis / Q000662:veterinary
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D012367:RNA, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines
keywords: Epizootic hemorrhagic disease virus serotype 2; Live attenuated vaccines; Pregnant cows; Transplacental transmission; Vaccine safety