Antibody protection against lethal MAYV challenge. A lethal MAYV challenge model was developed by treating 4 wk-old C57BL/6J male mice with a single 100-µg dose of anti-Ifnar1 mAb 1 d before subcutaneous virus inoculation. (A and B) Prophylaxis studies. A single dose of anti-MAYV mAbs (100 µg/mouse; ∼6/mg/kg) was administered 1 d before inoculation with MAYV-BeH407, and survival was monitored. Antibodies are presented in IgG subclass groups: mouse IgG1 (A) or mouse IgG2a (B). Data are from two experiments. (C and D) Therapeutic studies. Indicated mAbs (100 µg/mouse) were given 1 d after virus inoculation, and survival was monitored. Data are from two experiments. (E–G) Combination mAb therapy. 200 total µg of MAY-115, MAY-134, or a combination (100 µg each) was given to mice beginning at 1, 2, or 3 dpi, and survival was monitored. Data are from two experiments. In this figure, n = 10, log-rank test with Bonferroni correction compared with the isotype mAb control treated group. *, P < 0.05; ***, P < 0.001.