Recombinant capripoxviruses expressing proteins of bluetongue virus: Evaluation of immune responses and protection in small ruminants

The development of recombinant capripoxviruses for protective immunization of ruminants against bluetongue virus (BTV) infection is described. Sheep (n = 11) and goats (n = 4) were immunized with BTV recombinant capripoxviruses (BTV-Cpox) individually expressing four different genes encoding two capsid proteins (VP2 and VP7) and two non-structural proteins (NS1, NS3) of BTV serotype 2 (BTV-2). Seroconversion was observed against NS3, VP7 and VP2 in both species and a lymphoproliferation specific to BTV antigens was also demonstrated in goats. Finally, partial protection of sheep challenged 3 weeks after BTV-Cpox administration with a virulent strain of BTV-2, was observed.