title: First assessment of classical swine fever marker vaccine candidate CP7_E2alf for oral immunization of wild boar under field conditions.
abstract: Oral vaccination against classical swine fever (CSF) is a potent tool to control disease outbreaks in wild boar. So far, vaccination campaigns have been carried out using live attenuated vaccines that do not allow serological differentiation of infected from vaccinated animals (DIVA). Although this drawback is acceptable for wild boar, the use of marker vaccines would facilitate studies on disease and vaccination dynamics. Recently, the CSF marker vaccine candidate CP7_E2alf was assessed for oral immunization under laboratory conditions. Promising results prompted efforts to study the vaccine candidate under field conditions and in bait formulation. In this context, two oral vaccination campaigns were carried out with CP7_E2alf bait vaccines in two areas called 'faunistic-hunting farms' in the region of Umbria, Italy. One campaign was conducted using single vaccination, the second with the routinely employed double vaccination strategy. Both campaigns were carried out before concerted hunting actions were performed. Bait uptake, vaccine virus detection and antibody responses were assessed along with inspections upon gutting. As a comparator, seven wild boar were hand-fed with baits under laboratory conditions. In the field, bait uptake ranged from 63.7% to 98.7%, whereas antibody prevalence reached only 33.3-35.1%. The marker serology showed a strong influence of sample quality on the test outcome with a total of 85% of samples being classified correctly. Vaccine virus was not detectable. Under hand feeding conditions, six out of seven wild boar took up at least one bait, and five of them showed detectable antibody levels seven weeks after vaccination. These results were supplemented by stability tests. Appropriate stability of vaccine virus was shown both under field and laboratory conditions. In total, most results were in line with our expectations. However, optimization of the DIVA assay has to be attempted in the future.
authors.affiliation: Istituto Zooprofilattico Sperimentale Umbria e Marche, via Salvemini 1, 06126 Perugia, Italy. Electronic address: f.feliziani@izsum.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Feliziani
authors.affiliation: Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493 Greifswald-Insel Riems, Germany. Electronic address: sandra.blome@fli.bund.de.
authors.forename: Sandra
authors.initials: S
authors.lastname: Blome
authors.affiliation: Istituto Zooprofilattico Sperimentale Umbria e Marche, via Salvemini 1, 06126 Perugia, Italy. Electronic address: s.petrini@izsum.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Petrini
authors.affiliation: Istituto Zooprofilattico Sperimentale Umbria e Marche, via Salvemini 1, 06126 Perugia, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Giammarioli
authors.affiliation: Istituto Zooprofilattico Sperimentale Umbria e Marche, via Salvemini 1, 06126 Perugia, Italy.
authors.forename: Carmen
authors.initials: C
authors.lastname: Iscaro
authors.affiliation: Istituto Zooprofilattico Sperimentale Umbria e Marche, via Salvemini 1, 06126 Perugia, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Severi
authors.affiliation: Servizio gestione faunistica e protezione ambientale, Provincia di Perugia, via Pievaiola 140, 06132 Perugia, Italy. Electronic address: luca.convito@provincia.perugia.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Convito
authors.affiliation: Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493 Greifswald-Insel Riems, Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Pietschmann
authors.affiliation: Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493 Greifswald-Insel Riems, Germany. Electronic address: martin.beer@fli.bund.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Beer
authors.affiliation: Istituto Zooprofilattico Sperimentale Umbria e Marche, via Salvemini 1, 06126 Perugia, Italy. Electronic address: gm.demia@izsum.it.
authors.forename: Gian Mario
authors.initials: GM
authors.lastname: De Mia
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D006691:Classical Swine Fever / Q000517:prevention & control*; D004355:Drug Stability; D005260:Female; D007558:Italy; D008297:Male; D034421:Sus scrofa / Q000276:immunology*; D013552:Swine; D013696:Temperature; D014611:Vaccination / Q000379:methods*; D014765:Viral Vaccines / Q000008:administration & dosage* / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D014765:Viral Vaccines
keywords: CP7_E2alf; Classical swine fever virus (CSFV); Field trial; Marker vaccine candidate; Oral immunization; Wild boar