GENEVA, Switzerland, May 23 (UPI) -- The World Health Organization in Switzerland says it's revising its warning system to reflect the deadliness of a disease and not just its geographic spread.

The current six-point system was created in 2005 amid the threat from H5N1 bird flu, which has a fatality rate of about 60 percent. The six-point system reflects the spread of a virus but not its lethality.

Some countries have complained the current warning system caused panic when WHO announced the swine flu epidemic in April, though the strain has proved less deadly than bird flu.

In revising the warning system, WHO will try to "walk a fine line between not raising panic and not being complacent," Dr. Keiji Fukada, WHO's deputy director-general said in Geneva Friday.

With the swine flu, WHO quickly raised its alert level to 4 and then 5 after the virus was reported spreading from Mexico in April. The agency has not gone to level 6 -- signifying the spread to a new continent -- even though cases of swine flu virus have been reported in Britain, Spain and Japan.