In Vietnam, the Agriculture Ministry on Friday said bird flu outbreaks had hit Phu Tho, Thai Binh and Hoa Binh provinces, and added that the number of dead and slaughtered poultry in cities and infected areas since early October had reached nearly 900,000.
A Vietnamese researcher said a human vaccine was ready for testing and, if tests on volunteers went well, mass production would begin in the second quarter of 2006. Bird flu has killed 42 people in Vietnam.
China's Agriculture Ministry said an epidemic of highly pathogenic bird flu had been discovered in northern Shanxi province, a day after confirming its first human deaths from the H5N1 virus, but gave no further details.
Leaders of 21 Pacific Rim nations, holding their annual summit in the South Korean port city of Pusan, meanwhile put discussion of ways to contain the disease and prevent a human pandemic high on their agenda.
Australian Prime Minister John Howard told business leaders meeting alongside the Asia-Pacific Economic Cooperation (APEC) summit that he would announce "a very significant initiative" on the disease on Saturday.
"Appropriate responses to the potential pandemic will be high on the agenda" at the APEC summit, Howard said, emphasising "the importance of putting aside any sense of national pride or self-consciousness about any outbreak in individual countries".
In London, the leading medical journal The Lancet called on governments to communicate honestly and openly with the public.
Governments "must admit to uncertainty, act transparently, issue guidance on disease protection and make sure information is disseminated to the public as quickly as possible" to avoid panic even before a pandemic emerges, it said in an editorial.
Experts fear the bird flu could
mutate and cause a pandemic
A lethal strain of the H5N1 bird flu virus has killed 67 people of the 130 it has infected in Asia since late 2003, but the real fear is that it will mutate and acquire the ability to pass from human to human, causing a global pandemic.
In Nairobi, a UN official said the world body would set up an early warning system to alert countries to the approach of migrating birds that might be carrying the flu virus, so that they could take steps to prevent poultry being infected.
Early warning system
UN official Robert Hepworth said that the world body wanted to pull together data from a range of sources on the routes and flight times of migratory birds, which carry the flu virus and infect domestic flocks.
In Africa and other developing countries it is not practical to lock up poultry to keep it apart from wild birds, he said.
"The early warning system will pinpoint where the higher risk areas might be, so developing country officials can target those specific areas."
The system is being set up by the UN Environment Programme and the Convention on Migratory Species, which Hepworth heads, and will take one to two years to complete.