A significant influenza-driven recall response was generated in pigs vaccinated with the adjuvanted split vaccine in the CD4+CD8−, CD4+CD8+ and CD4−CD8+ subsets (4±1%, 16±4% and 12±1% CFSElow cells, respectively, P<0.05, n = 3, Figure 3B–D). Here, CD4 is linked to influenza.