Antiviral Agents/pharmacology; Fluorenes/pharmacology; Interferon Inducers/pharmacology; Nucleic Acids/pharmacology; Tilorone/pharmacology; Tobacco Mosaic Virus/pathogenicity; Animals; Antiviral Agents/administration & dosage; Birds; Cells, Cultured; Cytotoxicity Tests, Immunologic; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Encephalitis/drug therapy; Encephalitis Virus, Eastern Equine/pathogenicity; Encephalitis Virus, Western Equine/pathogenicity; Encephalitis, Tick-Borne/drug therapy; Haplorhini; Humans; Influenza, Human/drug therapy; Interferon Inducers/administration & dosage; Interferons/analysis; Macaca; Mice; Newcastle Disease/drug therapy; Nucleic Acids/administration & dosage; Tilorone/administration & dosage; Tilorone/toxicity; Time Factors