Aspects of human biomedical and immunological adaptation to Antarctic isolation was studied including the occurrence of respiratory virus infections in people overwintering in Antarctica and the reasons for their rapid loss of resistance to infection under these conditions. Winter over personnel are initially exposed to colds and other infections brought to Antarctica by summer support and ... scientific personnel at Scott Base and McMurdo Station. At this time, their immunity to these infections is maintained at normal levels. However, at the onset of winter isolation, the frequency of upper respiratory infections decreases and a consequent decline in immunity, often to sub normal levels occurs. Return to civilisation is often accompanied with an increased frequency of upper respiratory illness. In order to understand the immune mechanism involved, we need to know; a) the virus or viruses causing upper respiratory infections during the summer season and/or during winter isolation and b) the antibody levels to a particular virus or viruses in winter over personnel throughout the year. Blood, throat and nasal swabs and nasal wash samples were collected from Scott Base staff at four different periods; i) Pre Antarctic collection (October 1975 Christchurch), ii) Mid summer collection (December 1975 Scott Base), iii) Mid winter collections (August, 1976 McMurdo) and iv) Win Fly collection (September 1976 Scott Base). In addition, specimens were taken from acute upper respiratory cases occurring in both winter over or summer support personnel during the summer season, when possible. Cell culture facilities were established at the Eklund Biological Centre to provide the best possible conditions for virus isolation at McMurdo and Scott Base. Samples were inoculated directly into cell culture for the isolation of viruses. The facility was also transferred to the biomedical laboratory at the South Pole Station to monitor the spread of virus infections to this base. A total of 11 viral isolated were made from specimens collected and directly inoculated into cell culture either at McMurdo, Scott Base or South Pole Station.