VACCINIA VIRUS EXPRESSION OF THE VP7 PROTEIN OF SOUTH-AFRICAN BLUETONGUE VIRUS SEROTYPE-4 AND ITS USE AS AN ANTIGEN IN A CAPTURE ELISA

Recombinant vaccinia viruses expressing the VP7 core protein of South African bluetongue virus serotype 4 (SA-BTV4) were identified by polym erase chain reaction amplification. Expression of VP7 was verified by radio-immunoprecipitation and a F(ab')(2)-based ELISA. Antibodies to V P7 were detected in sera from sheep that had been infected with 20 dif ferent virulent BTV serotypes by using the vaccinia virus (VV) express ed VP7 as antigen in a capture ELISA. F(ab')(2)-immobilised VV-express ed SA-BTV4 VP7 crossreacted with sera directed against all 9 African h orsesickness virus serotypes and epizootic haemorrhagic disease virus serotype 2.