The protective immune response against Pseudorabies virus induced by DNA vaccination is impaired if the plasmid harbors a functional Porcine circovirus type 2 rep and origin of replication

► A replicative plasmid harboring PCV2 Ori-rep was evaluated as a DNA vaccine vector. ► This plasmid was compared to a non-replicative PCV2-derived plasmid. ► These plasmids were used to vaccinate pigs against Pseudorabies virus infection. ► Pigs were more affected by PrV-infection with the replicative plasmid. ► This study shows an in vivo deleterious effect of PCV2 Ori-rep on PrV protection.