The Virology Core will provide fundamental, well-established services in respiratory virology to project investigators for Projects 1, 2, 3, 4 and 5. Dr. Frederick Henderson will be the Virology Core director and Dr. Melinda A. Beck will be the Co-Director. The virology core will provide the following services: 1) Isolation of viruses in respiratory secretions of children with acquired acute respiratory illnesses or adults with experimental infections, 2) Identification of viruses from nasal secretions (antigen detection by ELISA and FA detection of antigen), 3) Quantitation of virus (RSV, influenza) from respiratory secretions or organs from experimentally infected animals, 4) Preparation of virus stocks, including providing gradient purified viruses, 5) measuring antiviral antibody, both binding and neutralizing, 6) Development of monoclonal antibodies requested by the Projects. Dr. Henderson and Beck will provide hands-on laboratory work as well as providing technical assistance to the technician, Ms. Huang. Dr. HU will assist with the development of monoclonal antibody production.