This occurred via proliferation starting between day 3 and day 7 post infection, paralleling the polyclonal CD8+ T-cell response and peaking at around day 10, when ∼85% (IQR 70–92%) of epitope-specific CD8+ T cells in blood showed activation and proliferation by CD38 and Ki-67 expression (Fig. 6c). This evidence concerns the gene CD38 and infection.