Virus neutralizing antibodies against a panel of 18 BVDV isolates in calves vaccinated with Rispoval (TM) RS-BVD

Seven of nine colostrum-deprived calves, free from infection with bovine vi rus diarrhoea virus (BVDV), were vaccinated with Rispoval(TM) RS-BVD on two occasions, 21 days apart, while the other two were kept as BVDV infection controls. The virus neutralizing (VN) Serum antibodies induced by vaccinati on were tested for their ability to neutralize 18 European BVDV isolates, i ncluding laboratory reference strains and recent field isolates, both cytop athic and non-cytopathic biotypes as well as genotypes I and II. The strain s were isolated in Belgium, France, Germany and the United Kingdom. While t here were large variations in the vaccine-induced TIN titres of the individ ual calves against all the strains, e.g. the titres against Osloss NCP, the European reference strain ranged from 1.7 to 6.7 (1:log(2)) serum from eac h animal was capable of neutralizing between nine and all 18 of the strains tested. Nevertheless, from the results of this study, it can be concluded that in colostrum-deprived BVDV seronegative calves, Rispoval(TM) RS-BVD ca n stimulate the production of VN antibodies capable of neutralizing a wide range of antigenically diverse European isolates of BVDV, including genotyp es I and II.