The interaction between porcine circovirus 2 and its natural hosts (domestic pig and wild boar) is a complex process. This process starts with viral attachment and entry into host cells. Viral replication happens in many different cell types, such as epithelial, endothelial cells and macrophages. This virus has a relatively long incubation period, around 18 and 25 days.
Porcine circovirus 2 sistemic diseade has higher viral load than porcine circovirus 2 subclinical infection. The acute infection of the host usually ends due to an adaptive response. Viral persistence after the acute infection is posible in pigs developing porcine circovirus 2 subclinical infection. On the other hand, pigs suffering from porcine circovirus 2 systemic disease usually show an altered cellular and humoral immune response.