But Chief Executive Clive Dix believes it may have a big advantage because it is not produced laboriously in chicken eggs, like conventional flu shots, and only tiny quantities will be needed to vaccinate large numbers of people.

Industry analysts, however, said the novel DNA-based approach to vaccination was still largely untested and would face close scrutiny from healthcare regulators.

"We're probably six months behind but we are in a unique position because we could produce enough vaccine in the first three months of pandemic to vaccinate everybody," he said.

"Just 1.2 kg of vaccine DNA would be sufficient to vaccinate the entire population of the US twice over."

PowderMed's vaccine is produced by cloning a gene from the current circulating bird flu strain and slotting it into an existing DNA backbone vaccine.

This "plug and play" system would enable the group to rapidly adapt the vaccine to include relevant DNA if a new and more dangerous strain develops, Dix said.

Public health experts fear the avian flu virus could mutate and develop the ability to spread easily from person to person, potentially killing millions in a flu pandemic.

So far, the H5N1 flu strain has killed more than 50 people in Asia, including in Vietnam, Thailand and Cambodia, and most recently Indonesia.

The governments of the United States, Britain, France, Canada and Australia have all recently announced plans to stockpile H5N1 vaccine, and a number of companies are working to make a suitable product.

Sanofi-Aventis SA is thought to be furthest ahead in the race but other Western vaccine groups are also busy in the area, along with companies in China and Vietnam.

PowderMed was created via a management buyout last year after US vaccine maker Chiron Corp acquired Britain's PowderJect Pharmaceuticals, the company which previously owned its powder-based DNA vaccine technology.