The influenza virus enzyme neuraminidase is an attractive antiviral target because its active site is highly conserved among many influenza A and B strains. Neuraminidase inhibitors are an exciting new class of antiviral drug that should help in the prevention and treatment of influenza infection. Encouraging new clinical data on the 2 most advanced neuraminidase inhibitors, GS-4104 and zanamivir, were presented at the 38th Interscience Conference on Antimicrobial Agents and Chemotherapy [San Diego, US; September 1998]. These data suggest that both agents could be useful in the prophylaxis and treatment of influenza A and B.