Viruses cause a number of devastating diseases of medical, veterinary and agricultural importance.
The spectrum of virus diseases ranges from asymptomatic to acutely fatal or chronically progressive and includes development of tumours. Viruses have been and remain at the forefront of research in molecular biology, cell-biology and immunology. Despite the detailed understanding of some aspects of virus genetics, structure and replication, many viruses remain a major challenge for public health. Human immunodeficiency virus and the AIDS epidemic and other new viruses such as Ebola and hepatitis C that are emerging or re-emerging are prominent examples but viruses such as influenza, measles, and the common cold remain important problems.