Vietnam's health officials are planning to start testing a potential human vaccine against the H5N1 bird flu virus in early 2006, it emerged yesterday, despite international warnings that developing a specific H5N1 vaccine would be futile if the virus mutates.

Pham Ngoc Dinh, deputy head of the National Hygiene and Epidemiology Institute, said that the vaccine was developed in 2004 and had been tested successfully on chickens and monkeys. Human trials would begin as soon as the World Health Organisation and the Vietnamese government approved the tests, Reuters reports.

Researchers in the country have also identified new strains of the flu in poultry. However, given the amount of attention the disease is getting, it should not be too surprising that new strains have been picked up.

"The presence of more subtypes of the flu virus in poultry make the virus all the more dangerous," Dong Manh Ha, director of Ho Chi Minh City Regional Animal Health Centre, told the news agency.

The new strains are not as virulent as the H5N1 strain that affects humans, nor do they seem to spread as quickly. But according to Lo Wing-lok, an expert in infectious disease based in Hong Kong, people could still be at risk, if the new strains are allowed to spread in bird populations.

Bird flu is still not easily spread to humans, nor have there been any confirmed cases of human-to-human transmission. ®

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