IFNG and infection: Peptides were pooled to represent PRRSV-1 proteins and recognition by PBMC assessed using an ex vivo IFN-γ ELISpot assay 21 days after infection (21 dpi) and 16 days after challenge (51 dpi) for both the Olot/91 (Figure 2) and SU1-Bel (Figure 3) groups.