CD38 and infection: Early in the infection (∼d10), the frequency of CD38+HLA-DR+CD8+ T cells in the recovery group reached a mean of 26.6% (CI 95%: 15.4–37.8% at the earliest time-point), then gradually declined (∼d14–d18) to 10.3% (CI 95%: 3.8–16.8%) as patients recovered (Fig. 1a, b).