Every country in the world must come up urgently with a plan to deal with an inevitable influenza pandemic likely to be triggered by the bird flu virus that hit Asia this year, a top global health expert said on Friday.

“I believe we are closer now to a pandemic than at any time in recent years,” said Shigeru Omi, regional director for the Western Region of the World Health Organization (WHO).

“No country will be spared once it becomes a pandemic,” he told a news conference.

“History has taught us that influenza pandemics occur on a regular cycle, with one appearing every 20 to 30 years. On this basis, the next one is overdue,” he said at a conference of 13 Asian health ministers trying to figure out how to avoid one.

“We believe a pandemic is highly likely unless intensified international efforts are made to take control of the situation,” he said of the H5N1 avian flu virus, which has defied efforts to eradicate it in several Asian countries, including Thailand.

The Spanish flu pandemic of 1918 and 1919 killed upwards of 20 million people. WHO experts say the next could infect up to 30 percent of the world’s more than 6 billion people and kill up to 7 million of them.

Omi said that to stave that off, the world would have to cooperate closely by sharing information promptly and openly on the virus - such as how it spreads, why it hits children more easily than adults and how quickly it is mutating.

Secrecy in China last year helped the deadly SARS virus spread to many other countries before it could be brought under control and Beijing has also been accused of hiding the extent of its AIDS epidemic.

“Vaccine will protect you from the disease and reduce the impact individually. But vaccination alone will not prevent this outbreak,” Omi said.

“Each country has to come up with a plan because, as I said, a pandemic, it will happen.”

HUGE HUMAN TOLL

Two U.S. firms are working on a vaccine, but neither is likely to have one ready until March, well after the cooler Asian season in which bird flu thrives best.

The H5N1 virus, which has already killed 20 Vietnamese and 12 Thais, arrived in Asia about a year ago, probably spread by migrating birds, especially wild fowl heading to warmer climes at the onset of the northern winter.

Governments have slaughtered tens of millions of poultry in a bid to eradicate it but WHO experts say it is now probably a permanent fixture.

The wild birds, which can carry the virus without falling ill, are flying south through Asia to escape the northern winter and, in an alarming development, domesticated ducks are showing they too can have the virus without showing it, Omi said.

Experts say a pandemic will emerge from an animal, most probably a pig, which can harbour both flu viruses that affect humans and the avian flu variety. The two strains could then exchange genetic material and produce a virus to which people have no immunity, they say.

That has not happened yet, but Omi said the geographical spread and the impact of the H5N1 virus was unprecedented and had struck animals such as tigers and domesticated cats not previously known to be susceptible to avian flu viruses.

“We have found that the virus is resilient, very, very versatile,” Omi said.

The Asian health ministers - from Brunei, Cambodia, China, Indonesia, Laos, Japan, South Korea, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam - promised they would make plans for a pandemic and cooperate to stave it off.

In a joint statement at the end of the two-day meeting, they pledged to work together to develop vaccines, diagnostic tests for humans and research urgently needed to provide more information on the virus.