CD4 and infection: Regulatory T-cells (TREG, CD4+CD44+FoxP3+) ranged from 20% - 25% of activated CD4+ T-cells during UgCl223 infection (Figure 8A) and, unlike in lethal KN99α infections (Wiesner et al., 2016), were present at significantly lower levels compared to the predominant TH1 effector cell populations at all but the 0- and 77- day timepoints.