A genetically engineered chimeric vaccine against porcine circovirus type 2 (PCV2) improves clinical, pathological and virological outcomes in postweaning multisystemic wasting syndrome affected farms

The present study describes the effects of a commercially available genetically engineered chimeric vaccine against porcine circovirus type 2 (PCV2) on clinical, pathological and virological features in three multi-site farms suffering from postweaning multisystemic wasting syndrome (PMWS). The vaccine product was able to reduce clinical signs, PCV2 viral load in lymphoid organs and/or sera, and overall mortality in nurseries and fattening units. This is the first time in which is shown that a PCV2 vaccine is able to decrease specifically PMWS-associated mortality. Another novelty of this study is the assessment of PMWS-like histological lesions in a large number of vaccinated and non-vaccinated pigs under field conditions.