The World Health Organization (WHO) says one-third of the world population could become infected with H1N1 influenza.

WHO Assistant Director-General Keiji Fukuda made the remark at a press conference in Geneva on Friday, saying that such a projection is based on previous cases of flu pandemics. He added that it is not an official estimate of what might occur with the virus, but a warning of what could lie ahead if the outbreak continues to worsen.

He added that the U.N. will maintain its level five alert on its six-tier scale, explaining that the flu does not seem to be a full pandemic yet.