CD8A and influenza: When the CD8+ T cell kinetics to the vaccine regimen were followed over time in the blood of T-Atg7−/− mice, influenza-specific CD8+ T cells were detected at normal frequencies to primary immunization but the secondary ‘booster’ vaccine was unable to induce an increase in NP-specific CD8+ T cell frequency like it could in wild-type mice (Figure 5C).