Anti-CD137 MAb treatment reduces levels of MAYV RNA in the spleen, DLN, and ipsilateral foot. Four-week-old WT C57BL/6 male mice were inoculated with 103 FFU of MAYV BeH407. At 2 dpi, 400 μg of agonistic anti-CD137 MAb or isotype-control MAb was administered via the i.p. route. Ipsilateral (A) and contralateral (B) feet, spleen (C), and DLN (D) were harvested at 14 dpi. Viral RNA from tissue homogenates was measured by qRT-PCR. Each symbol represents an individual mouse, and bars indicate median values. Data were pooled from three experiments. ***, P < 0.001; ****, P < 0.0001; n.s., not significant, Mann-Whitney test.