IFNG and infection: The evaluation of the IFN-γ productivity during the PE period, and specifically after PCV2 natural infection, highlighted different features when comparing PCV2-vac and control pigs: 1) in some PCV2-vac animals, a lower IFN-γ SC response was characterized by a stable cell frequency and increase of IFN-γ productivity depending on the recall PCV2 antigen amount (Figure 9A); 2) in some control animals, a much higher SC response was characterized by an increasing cell frequency and stably lower IFN-γ productivity depending on the recall PCV2 antigen amount (Figure 9B).