title: Viraemia and clinical disease in Dorset Poll sheep following vaccination with live attenuated bluetongue virus vaccines serotypes 16 and 4.
abstract: The spread of bluetongue virus (BTV) is most successfully controlled by vaccination of susceptible ruminant populations. Currently two different types of BTV vaccines are used for this purpose; inactivated, mostly monovalent vaccine formulations and modified live virus vaccines (MLVs). Clinical signs and viraemia in Dorset Poll sheep vaccinated with BTV-4 and BTV-16 MLVs or inoculated with homogenates of midges (C. sonorensis and C. nubeculosus) previously infected with BTV-4 MLV are presented. All sheep vaccinated with the two MLVs mounted an infectious viraemia lasting for a minimum of 9 up to 23 days post vaccination and developed a range of clinical signs associated with BTV infection. Peak viraemia titres recorded in individual sheep ranged from 3.5 to 6.83 log(10)TCID(50)/ml indicating a high potential for infection of vector insects and onward transmission. The implications of these results are discussed with reference to the current outbreaks of BTV occurring in northern Europe and in relation to the future development of vaccines for this virus.
authors.affiliation: Institute for Animal Health, Vector-borne Disease Programme, Ash Road, Pirbright, Woking, Surrey, GU24 ONF, UK. eva.veronesi@bbsrc.ac.uk
authors.forename: Eva
authors.initials: E
authors.lastname: Veronesi
authors.forename: Karin E
authors.initials: KE
authors.lastname: Darpel
authors.forename: Chris
authors.initials: C
authors.lastname: Hamblin
authors.forename: Simon
authors.initials: S
authors.lastname: Carpenter
authors.forename: Haru-Hisa
authors.initials: HH
authors.lastname: Takamatsu
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Anthony
authors.forename: Heather
authors.initials: H
authors.lastname: Elliott
authors.forename: Peter P C
authors.initials: PP
authors.lastname: Mertens
authors.forename: Philip S
authors.initials: PS
authors.lastname: Mellor
mesh_terms: D000818:Animals; D001819:Bluetongue / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D001820:Bluetongue virus / Q000276:immunology*; D002519:Ceratopogonidae / Q000821:virology; D005260:Female; D007303:Insect Vectors / Q000821:virology; D008297:Male; D012756:Sheep; D013997:Time Factors; D014611:Vaccination; D015164:Vaccines, Inactivated / Q000276:immunology / Q000494:pharmacology; D014765:Viral Vaccines / Q000276:immunology / Q000494:pharmacology*; D014766:Viremia / Q000276:immunology*
chemical_list: D015164:Vaccines, Inactivated; D014765:Viral Vaccines