Antiviral drugs are vital, but imperfect tools for treatment and prevention of viral infections. Undesirable effects, from drug resistant viruses to low oral bioavailability, toxicity and severe side effects limit clinical usefulness. All these issues drive the need for improved antiviral strategies. This book offers an up-to-date review of new drugs and targets, novel modes of action, vector-based treatments and even the blocking of defined genes by inhibiting mRNA formation (siRNA). Highlights include the discussion of novel, promising compounds; concepts of therapy for new/emerging viruses; managing drug resistance; new therapeutic strategies. Contributions were carefully selected to ensure quality coverage by acknowledged experts over a wide spectrum and will be of great value to students and serve as a compendium for R&D and educational professionals.