Attenuated Live Bluetongue Virus 8 Vaccine Protects Sheep from Challenge with the European BTV-8

Abstract

An attenuated live bluetongue virus (AL-BTV) serotype 8 vaccine of South African origin was evaluated for its ability to protect sheep against challenge with a European BTV-8 isolated from an outbreak. Two groups of sero-negative sheep were vaccinated with either a single or booster vaccination and challenged subcutaneously 28 days following vaccination.Groups of vaccinated challenged sheep showed no clinical signs typical to Bluetongue disease, as compared to unvaccinated inoculated sheep of a control group. A clinical reaction index (CRI) of values ranging from 0 to 5 was determined for each of the groups, where vaccinates measured a CRI of less than 1 and the control sheep measured a CRI of at least 4.5.All vaccinated sheep developed high serotype-specific neutralizing antibodies post-vaccination. The results indicated that a single dose of the AL-BTV-8 was sufficient to protect vaccinated sheep against a virulent challenge of the European BTV-8 outbreak isolate.

Duration of protective immunity after a single vaccination with a live attenuated bivalent bluetongue vaccine

“…Vaccination with MLV and inactivated viruses produces neutralizing and group-specific antibodies (Oura et al 2009 ; Hamers et al 2009 ) protecting the vaccinated animal against challenge. Live-attenuated vaccines usually elicit a strong immune response, with the development of antibodies, and are usually efficacious after a single dose (Patta et al 2004 ; Dungu et al 2008 ).…”

Bluetongue virus vaccine: conventional to modern approach

“…A single dose of LAV also elicits sufficient immune response and protective immunity against virulent strain of European BTV serotype 8 in sheep. Post vaccination, vaccinated animals didn't show any clinical signs, while the unvaccinated sheep showed severe clinical signs of BT (Dungu et al, 2008).…”