Population of PRRSV specific IFN-γ
total lymphocyte response in the blood of pigs. PBMC isolated from individual pigs at 26 dpv (A–C) and 14 dpc (D–F) were unstimulated (control) or stimulated with PRRSV strain 1-4-4 (virus) or pooled five conserved peptides (peptides). IFN-γ secreting cells in total CD3ε+ lymphocytes and NK cells (CD3ε−CD4α−CD8α+) are shown. Each bar represents the average cell counts of 50 000 events from 4 or 5 pigs ± SEM. Lowercase alphabet and asterisks indicate a statistically significant difference (a or *P < 0.05, **P < 0.01 and *** P < 0.001) between control (PBS) and vaccine received groups under the same ex vivo stimulation condition, or between different stimulation conditions within the same treatment group.