Threatwatch: West Nile – what is the actual risk?

New Scientist The news this week is full of stories of West Nile virus, with Dallas, Texas declaring a health emergency and launching aerial insecticide spraying after 200 known cases and 10 deaths from West Nile this summer. But how much of a threat is the virus really? And could a minor bout of West Nile actually be your best protection for the coming years?