Why do viruses kill?.

A fascinating and hugely informative look at the life of viruses and how they affect human existence. The difficulties of predicting how much devastation might be caused by a pandemic such as the recent H1N1 flu strain (swine flu) is discussed by virologists and Ralph O'Connor, from the Centre for Disease and Control, describes how, at the start of the pandemic, it was estimated that 120 million people might die worldwide. Geoffrey Smith and Eckard Wimmer give detailed descriptions of how viruses look and reproduce. Curtis Suttle describes the diversity of viruses' existence, particularly the viruses in the ocean. Mark Young travels to Yellowstone Park, Montana, and recounts his discovery that the earliest most archaic forms of life, archaea, were riddled with viruses. This means that viruses have infected life since it emerged; in fact, life probably could not have evolved without viruses. Professor John Oxford describes how easily flu viruses can be spread and about how different viruses affect us, including smallpox, HIV and rabies as well as detailing the process by which an animal virus can pass to a human. On this subject, epidemiologist Anne Rimion, shows her work with monkeypox, the next virus that might possibly pass from animal to human. DA Henderson describes his work with the smallpox virus and the 1967 World Health Organisation's eradication of the virus by mass vaccination. However, viruses that mutate are harder to vaccinate against - this is particularly true of HIV which mutates at an alarming rate. Eckart Wimmer describes his research to create a virus from a piece of synthetic DNA. All virologists, however, warn against thinking we should ever try to eradicate viruses, even if it were possible, as they are a vital part of our evolution and survival.