Nef responses as measured by ELISpot. (A) IFN-γ and (B) IL-2 secretion by splenocytes stimulated with either a pool of overlapping peptides covering Nef or a pool of control peptides (Tick Borne Encephalitis virus, TBE). * indicates a significant difference (p < 0.05). Error bars show standard deviations of all animals in each group. (C) IFN-γ secretion by pooled splenocytes from all animals in each group (black bars) or by pooled splenocytes depleted of CD8 + cells (white bars). M = MVA, D = DNA.