New antiviral drugs Entry inhibitors Receptor interactions are very specific(-but often alternative routes for entry exist) Fusion inhibitors Protease inhibitors Very specific if virus-encoded Herpesvirus Hepatitis C virus · not influenza Nucleic acid synthesis and processing RNA-dependant RNA polymerase Virus-specific helicases Herpesvirus cleavage/ packaging Small interfering RNA (si RNA), antisense RNA, and ribozymes Regulatory proteins Virus Release/ spread, antisense RNA, and ribozymes