Antibody responses to inactivated vaccines and natural infection in cattle using bovine viral diarrhoea virus ELISA kits: assessment of potential to differentiate infected and vaccinated animals.

Bovine viral diarrhoea virus (BVDV) is one of the most common and economically important viral infections of cattle. As vaccination is common in most European countries, differentiation between infected and vaccinated animals is one of the key challenges facing BVDV eradication campaigns. This study was designed to compare the ability of commercial ELISA kits to differentiate antibodies generated following vaccination with four different commercial inactivated BVDV vaccines from antibodies generated following challenge with virulent BVDV. Although none of the tested vaccine-ELISA combinations was able to differentiate an infected from a vaccinated animal (DIVA) at the individual animal level, p80 blocking ELISAs, in combination with inactivated BVDV vaccines, may have some value under certain circumstances at herd level. In most cases, antibody responses to BVDV vaccines cannot be clearly distinguished from responses seen in the early phase of natural infection. No commercial BVD vaccine showed true marker qualities for DIVA using p80 blocking ELISAs.