Figure 1. WNV-E218A is attenuated in wild-type mice and cells but is virulent in Ifnar1−/− mice and cells.
a, Survival curves of wild-type and Ifnar1−/− C57BL/6 mice after subcutaneous infection with WNV-WT or WNV-E218A. b, Virus replication in wild-type mice in blood (day 4), spleen (day 4) or brain (day 8) after subcutaneous infection with WNV-WT or WNV-E218A. c, Survival curves of wild-type mice after intracranial infection with WNV-WT (101) or WNV-E218A (105 plaque-forming units (PFU)). d, Viral burden in the serum, spleen, kidney, spinal cord and brain from Ifnar1−/− mice at day 3 after infection. e, f, Replication of WNV-WT and WNV-E218A in wild-type or Ifnar1−/− MEFs (e) or Mφ (f). Results are the average of three experiments performed in triplicate. Error bars, s.d.; dashed line, limit of sensitivity of the assay.