Swine flu may be 'relatively mild'
Updated on 30 April 2009
Swine flu may well spread across the globe, but the illness it causes will be relatively mild.
The virus may not become the fatal pandemic some have feared, according to a leading scientist who has been studying the flu.
Fears that young, fit people aged between 25 and 40 are most at risk may also be unfounded.
Swine flu is now present in 13 countries, with Ireland, the Netherlands and Switzerland confirming their first cases today.
Three more people in the UK also tested positive. All are just back from Mexico.
Channel 4 News explains how the virus mutated over decades into its present form, from a series of animal and human organisms.
