Avian flu has devastated poultry farms and wild bird populations around the world and now it's spread to mammals such as mink and seals. Cases in humans have been rare but worryingly fatal in more than half of the recorded incidences. How worried should we be about the risk of a new global pandemic?

Joining David Aaronovitch in The Briefing Room are:

Wendy Barclay, Head of the Department of Infectious Disease and Chair in Influenza Virology at Imperial College London

Producers: Kirsteen Knight, Cecilia Armstrong and Ben Carter