Recent research of Taubenberger et al. has suggested that the 1918 virus, like H5N1, could have arisen directly from an avian influenza virus.[11] However, researchers at University of Virginia and Australian National University have suggested that there may be an alternative interpretation of the data used in the Taubenberger et al. paper.[17][18] Taubenberger et al. responded to these letters and defended their original interpretation.[19]