The aim of this guideline is to outline the procedure to be followed by the Competent Authorities when a batch of a vaccine is suspected to be contaminated with bovine viral diarrhoea virus (BVDV). Considering the risk of BVDV in bovine serum, the highest risk will be with live and inactivated vaccines indicated for use in pestivirus susceptible species (bovine, porcine, ovine, caprine).