CD8A and influenza: As our earlier analysis of influenza-specific CD8+ TCR clonotype diversity has focused on the prominent Vβ8.3+DbNP366+[44], [46] and Vβ7+DbPA224+ sets [47], we first assessed the Vβ mAb-staining profiles to determine whether these characteristic TCRs were also selected following primary or secondary challenge of aged mice.