"GENEVA -- The World Health Organization declared an influenza pandemic on Thursday and called on governments to prepare for a long-term battle against an unstoppable flu virus.

The United Nations agency raised its pandemic flu alert to phase 6 on a six-point scale, indicating the first influenza pandemic since 1968 is under way.

'With today's announcement, WHO moves from an emergency to a longer-term response. Based on past experience, this pandemic will be with us for some months, if not years, to come,' WHO Director-General Dr Margaret Chan said in a letter to staff, a copy of which was obtained by Reuters."

Stephanie Nebehay reports for Reuters June 12, 2009. [2]