title: Persistence of the protective immunity and kinetics of the isotype specific antibody response against the viral nucleocapsid protein after experimental Schmallenberg virus infection of sheep.
abstract: Schmallenberg virus (SBV) is an Orthobunyavirus that induces abortion, stillbirths and congenital malformations in ruminants. SBV infection induces a long lasting seroconversion under natural conditions. The persistence of the protective immunity and the isotype specific antibody response upon SBV infection of sheep has however not been studied in detail. Five sheep were kept in BSL3 facilities for more than 16 months and subjected to repeated SBV infections. Blood was regularly sampled and organs were collected at euthanasia. The presence of SBV RNA in serum and organs was measured with quantitative real-time PCR. The appearance and persistence of neutralizing and SBV nucleoprotein (N) isotype specific antibodies was determined with virus neutralization tests (VNT) and ELISAs. The primo SBV infection protected ewes against clinical signs, viraemia and virus replication in organs upon challenge infections more than 15 months later. Production of neutralizing SBV specific antibodies was first detected around 6 days post primo-inoculation with VNT and correlated with the appearance of SBV-N specific IgM antibodies. These IgM antibodies remained present for 2 weeks. SBV-N specific IgG antibodies were first detected between 10 and 21 dpi and reached a plateau at 28 dpi. This plateau remained consistently high and no significant decrease in titre was found over a period of more than 1 year. Similar results were found for the neutralising antibody response. In conclusion, the SBV specific IgM response probably eliminates SBV from the blood and the protective immunity induced by SBV infection protects sheep against reinfection for at least 16 months.
authors.affiliation: CODA-CERVA, Operational Directorate Viral Diseases, Groeselenberg 99, 1180, Brussels, Belgium. antoine.poskin@coda-cerva.be.|CODA-CERVA, Coordination of Veterinary Diagnostics Epidemiology and Risk Analysis, Groeselenberg 99, 1180, Brussels, Belgium. antoine.poskin@coda-cerva.be.
authors.forename: Antoine
authors.initials: A
authors.lastname: Poskin
authors.affiliation: ID Vet, Service développement, 310 Rue Louis Pasteur, 34790, Grabels, France. stephanie.verite@id-vet.com.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Verite
authors.affiliation: ID Vet, Service développement, 310 Rue Louis Pasteur, 34790, Grabels, France. loic.comtet@id-vet.com.
authors.forename: Loic
authors.initials: L
authors.lastname: Comtet
authors.affiliation: CODA-CERVA, Coordination of Veterinary Diagnostics Epidemiology and Risk Analysis, Groeselenberg 99, 1180, Brussels, Belgium. yves.vanderstede@coda-cerva.be.|Department of Veterinary Virology, Parasitology and Immunology, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium. yves.vanderstede@coda-cerva.be.
authors.forename: Yves
authors.initials: Y
authors.lastname: Van der Stede
authors.affiliation: CODA-CERVA, Operational Directorate Viral Diseases, Groeselenberg 99, 1180, Brussels, Belgium. brigitte.cay@coda-cerva.be.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Cay
authors.affiliation: CODA-CERVA, Operational Directorate Viral Diseases, Groeselenberg 99, 1180, Brussels, Belgium. nick.deregge@coda-cerva.be.|Department of Veterinary Virology, Parasitology and Immunology, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium. nick.deregge@coda-cerva.be.
authors.forename: Nick
authors.initials: N
authors.lastname: De Regge
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood / Q000378:metabolism; D000914:Antibodies, Viral / Q000097:blood / Q000378:metabolism*; D002044:Bunyaviridae Infections / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D007113:Immunity, Innate; D009500:Neutralization Tests / Q000662:veterinary; D019590:Nucleocapsid Proteins / Q000276:immunology*; D016851:Orthobunyavirus / Q000235:genetics / Q000276:immunology*; D012367:RNA, Viral / Q000032:analysis / Q000097:blood; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology* / Q000821:virology
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D019590:Nucleocapsid Proteins; D012367:RNA, Viral