Response to Bayry and Tough: Is RNAi useful for controlling foot-and-mouth disease outbreaks?

In their Letter in this issue, Bayry and Tough suggest that RNA interference (RNAi) might be of limited effectiveness in controlling highly contagious animal pathogens, such as foot-and-mouth disease (FMD) virus (FMDV). The authors raise important concerns, including the high genetic variability of FMDV, the large number of susceptible animals and problems with small interfering (si)RNA treatment, in addition to those identified by Grubman and de Los Santos in their Trends Research Focus article [1].