Extended duration of IL-7 treatment after the clonal expansion phase promotes accelerated viral clearance. Mice were infected with LCMV-Clone 13 and treated with either IL-7 or PBS as described in Figure 3. At days 8, 31, 44, and 90 PI, the virus titers in tissues of IL-7–treated or PBS-treated mice were quantified by plaque assay. Panel A shows virus titers in serum, lungs, and liver at different days PI in PBS- or IL-7–treated mice, and panel B illustrates the overall kinetics of viral clearance.