Is swine flu a mild infection and therefore no cause for concern?

• We must not be complacent. It is too soon to assume it will be a mild infection. We don't know the profile of the virus and at present we are closely monitoring each case that comes up.
• Everyone who has contracted the virus in this country has been diagnosed early and treated with antivirals, which reduce the severity of symptoms.
• Flu viruses change character rapidly. They essentially evolve with the "fast forward" button switched on. That means the flu virus is unstable. It can pick up and swap genetic material, which can dramatically change its character – increasing the severity of symptoms.
  
• The virus could change in the autumn so we need to plan for all eventualities.