In this work, we study the consequences of sequence variations of the "2009 
H1N1" (swine or Mexican flu) influenza A virus strain neuraminidase for drug 
treatment and vaccination. We find that it is phylogenetically more closely 
related to European H1N1 swine flu and H5N1 avian flu rather than to the H1N1 
counterparts in the Americas. Homology-based 3D structure modeling reveals that 
the novel mutations are preferentially located at the protein surface and do not 
interfere with the active site. The latter is the binding cavity for 3 currently 
used neuraminidase inhibitors: oseltamivir (Tamiflu), zanamivir (Relenza) and 
peramivir; thus, the drugs should remain effective for treatment. However, the 
antigenic regions of the neuraminidase relevant for vaccine development, 
serological typing and passive antibody treatment can differ from those of 
previous strains and already vary among patients.
REVIEWERS: This article was reviewed by Sandor Pongor and L. Aravind.