Nature 472, 481–485 (2011); doi:10.1038/nature09907

We have recently discovered that the WNV-GFP stock used in the data set (Fig. 2 and Supplementary Table 8 of the original Letter) for West Nile virus (WNV) in this Letter was actually Venezuelan equine encephalitis virus (VEEV-GFP). The error has been tracked to a technical mistake made during the virus production process. This error affected the panels labelled WNV in Fig. 2, Supplementary Fig. 9, and Supplementary Table 8 of the original Letter; the Supplementary Information to this Corrigendum contains the corrected WNV data sets. This error also affected figure labels in our later work1 (see the Corrigendum to ref. 1).