Figure 1: Level of PCV2 in serum (copies per mL of serum) of pigs from PMWS-free herds in unit B (study II) at arrival and at termination of the study. Pigs showing no signs of PMWS (black); pigs with confirmed PMWS (white) and pigs showing signs of PMWS, but which did not fulfil the criteria at necropsy (black and white).