As the flu season and the threat of avian flu comes closer, Professor John Oxford from the Royal London Hospital discusses what the flu is, where flu comes from and whether drugs and vaccines can prevent human and avian influenza. Professor Pat Troop, Chief Executive of the Health Protection Agency, describes the systems in place to stop an avian flu outbreak from spreading, and Dr Paul Digard, from the Division of Virology at the University of Cambridge, tells us how the flu virus escapes through layers of mucus in the nose. Meanwhile, in the Naked Scientists laboratory this week, Dave and... Like this podcast? Please help us by supporting the Naked Scientists