This contract is one part of the pre-clinical portion of the NIAID Antiviral Substances Program. The Program supports five separate awards to investigators who have developed animal models of viral infections which can be used to test the activity of antiviral agents in vivo. Compounds are evaluated for efficacy both therapeutically and prophylactically. Studies of drug toxicity and effects of drug treatment on the immune response to infection are also pursued. Combination chemotherapy studies are encouraged. The currently awarded series of contractors have at their disposal the following models: University of Utah - herpes encephalitis in mouse, neonatal herpes in mouse, genital herpes in the guinea pig; University of Massachusetts - influenza in the mouse; Yale University - cytomegalovirus in the guinea pig; Baylor College of Medicine - respiratory syncytial virus in the cotton rat, and Tulane University - simian varicella and parainfluenza type 3 in the African Green monkey.