Abstract
Failure to translate discoveries about the etiology of viral respiratory infections into effective vaccines has stimulated research into antiviral chemotherapy. Volunteers whose antibody status before challenge is known and who have been exposed to a known dose of virus at a defined time provide an objective system for controlled observation of antiviral chemotherapy. A perspective on experience with drugs of five different categories of mechanisms of action is presented. Prophylactic and possibly therapeutic control of influenza and rhinovirus infections is possible. Field trials have confirmed that some regimens have beneficial effects and have shown the clinical restrictions of others. Chemotherapy is enhanced by immunoprophylaxis, and vice versa. If the potential of antiviral chemotherapy for clinical use is to be realized, complex virologic problems (some related to drugs and others unrelated) must be overcome. The groundwork is laid for new directions and new successes in the prevention and treatment of viral respiratory diseases with antiviral drugs.