MANILA, Dec. 9 (Xinhuanet) -- The World Health Organization (WHO)Thursday warned that the recent appearance and widespread distribution of an avian influenza virus, Influenza A/H5N1, has the potential to ignite the next pandemic and result in unpredictable calamities.

    The WHO's Regional Office for the Western Pacific said in a statement that all countries should develop or update their influenza pandemic preparedness plans for responding to the widespread socioeconomic disruptions that would result from having large numbers of people unwell or dying.

    According to the WHO, the focus of the preparedness plans is an estimate of how deadly the next pandemic is likely to be, whose answers from experts have ranged from 2 million to over 50 million.

    However, the WHO said that the specific characteristics of a future pandemic virus cannot be predicted. It is also unknown how pathogenic a novel virus would be, and which age groups will be affected.

    The WHO noted that plans to maintain health care systems will be especially crucial since good health care will play a central role in reducing the impact of the virus.

    It forecast that even in the best case scenarios of the next pandemic, 2 million to 7 million people would die and tens of millions would require medical attention.

    "If the next pandemic virus is a very virulent strain, deaths could be dramatically higher," the WHO said.

    "The global spread of a pandemic cannot be stopped but preparedness will reduce its impact," it added.

    The WHO said that in next few weeks, it would be publishing a national assessment tool for member states to evaluate and focus national preparedness efforts and providing guidance on stockpiling antivirals and vaccines.

    Next week, the WHO will start an expert meeting on preparedness planning. It is also working to advance development of pandemic virus vaccines, and to expedite research efforts to understand themechanisms of emergence and spread of influenza pandemics. Enditem