CD8A and infection: The improved CD8+ T cell response includes (1) a mild increase in circulating epitope-recognizing CD8+ T cells but substantially more expansion in response to stimulation in vitro, (2) long-lasting activity over one year after infection without obvious change with age, (3) restricted Vα gene usage by TCRs recognizing LLL, and (4) shared transcriptome features associated with weaker activation-induced proliferation.