But Level 6 pandemic designation does not mean H1N1 virus is becoming more dangerous.
Johannesburg, South Africa
The term pandemic does not necessarily indicate the danger of a specific illness, but rather the fact that an illness has spread geographically, both across national borders and to entirely different regions.
WHO officials have noted that while they are raising their alert to the highest level, there are no indications that the swine flu virus is mutating or adapting, or becoming more dangerous.
"A move to level 6 is not a verdict on the severity of the virus," Scotland's Health Secretary Nicola Sturgeon told Scottish lawmakers on Thursday. "It simply means that the extent of global spread now fulfills the definition of a pandemic."