The incursion and circulation of more than nine different serotypes of Bluetongue virus (BTV) in central and northern Europe over the past fifteen years has resulted in decreased animal welfare and production losses. Vaccination is crucial for controlling BTV since conventional biosecurity measures have limited impact on vector-borne diseases. However, as current vaccines have no accepted characteristic allowing for the differentiation of infected from vaccinated animals (DIVA), the use of these products impairs sero-epidemiological surveillance and thus a quick return to BTV-free status as well as serological monitoring of vaccine efficacy in the field. Small ruminants show the most severe clinical signs following BTV infection, but cattle are the virus’s main amplifying host and when infected with certain BTV strains, such as BTV-8, they can also display clinical signs. However, protective bovine immune responses against BTV are poorly characterized and there is limited information available about the ability of commercial and experimental vaccines to induce clinical and virological protection against BTV infection in cattle. Our objective was to develop and evaluate the efficacy of a novel DIVA subunit vaccine against BTV-8 in cattle, that later may be developed into a multi-serotype vaccine. We produced recombinant VP2 of BTV-8 and NS1 and NS2 of BTV-2 and formulated the vaccine with the purified proteins and an ISCOM-based adjuvant (SubV). The DIVA characteristic of this vaccine is based on the detection of VP7 antibodies in infected animals, thereby enabling the detection of BTV infection of any serotype. In the first study, we evaluated the immunogenicity of SubV in comparison with a commercial inactivated vaccine against BTV-8. Cows were subcutaneously immunized twice at a 3-weeks interval with SubV (n=5), the commercial vaccine (n=5), or with placebo (n=5). Humoral and cell-mediated immune responses were monitored before each vaccination as well as at 3 and 6 weeks after the second immunization. Both vaccines induced similar serum neutralizing antibody titers and the specific IgG1 antibody responses detected against VP2, NS1, and NS2 were strongest in cows immunized with SubV. Furthermore, serotype cross-reactive humoral and cell-mediated immunological responses to BTV-8 were detected to NS2 and NS1 of BTV-2, respectively. In the second study, calves were immunized twice at a 3-weeks interval with either SubV (n=6) or placebo (n=6), then challenged with BTV-8 three weeks later in a Biosecurity level 3 facility. Whereas controls developed strong viremia and clinical signs of Bluetongue disease including fever, mucosal congestion, and stiffness, vaccinated calves did not show any of these signs and were strongly protected against BTV infection. Preliminary data indicate that vaccinated animals developed very strong serum neutralizing antibody responses following vaccination. Humoral and cellular immunological analyses are ongoing and clinical, virological, and immunological results of both studies will be presented during the meeting. Taken together, these data indicate that our novel subunit DIVA vaccine composed of only three BTV proteins is very effective against BTV-8 infection in cattle, and will also enable serological monitoring of any BTV serotype in circulation in vaccinated populations. Furthermore, the serotype cross-reactivity of NS1 and NS2 suggests that this vaccine may be expanded in the future to target multiple BTV serotypes through the addition of purified recombinant VP2 of other serotypes.