ReproSTAR® VL5 HB stimulates immunity against five strains of lepto, including L. hardjo-bovis, the most common cause of bovine leptospirosis in U.S. cattle. The vaccine contains an L. hardjo-bovis isolate from a U.S. herd that was experiencing poor conception rates and was diagnosed with L. hardjo-bovis. REPROSTAR contains campylobacteria (Vibrio) that helps protect against early breeding losses.