The world remains highly vulnerable to a possible severe flu pandemic and governments should increase surveillance, vigilance and preparedness, the World Health Organization (WHO) says.

“Nothing about influenza is predictable – including where the next pandemic might emerge and which virus might be responsible,” the United Nations health agency warned.

In a seven-page report on flu, WHO said that on many levels, the world is better prepared now than ever before for a flu pandemic. The level of alert is high, it said, and there is better surveillance of flu viruses in both animals and humans.