CD8A and infection: Although the frequency of antigen-specific CD8+ T cells statistically decreased to background levels in the blood of NFA2-HIS/Flt3LG mice, YFV-specific CD8+ T cells were readily detectable in the spleen by day 20 post infection but were not detectable in the spleen of NFA2-HIS/Fluc mice (Fig. 7d, Supplementary Figure 8g).