Laboratory tests on an experimental vaccine to protect poultry...

Laboratory tests on an experimental vaccine to protect poultry from a deadly strain of bird flu are set to begin in Australia , researchers said.

The genetically-modified vaccine aims to contain the virus that killed 27 people and led to the slaughter of an estimated 100 million chickens earlier this year when it swept through 10 Asian countries.

Scientists at the Australian government's CSIRO Livestock Industries said they had developed a vaccine to protect chickens from the flu strain H5N1, which could help contain future outbreaks.

CSIRO Livestock Industries deputy chief Chris Prideaux said previous influenza vaccines had the potential to cause fresh outbreaks because they contained all of the flu's genetic material.

But he said the Australian vaccine used only a small portion of the H5N1 strain's structure, reducing the risk of it reactivating.

"Most current vaccines are produced from live inactivated viruses," he said. "These vaccines can result in the virus persisting in the flock and potentially re-emerging to cause disease later on.

He said testing on chickens was about to begin and once developed, the vaccine could protect the world's poultry industry from further outbreaks and potential spread to Australia , Europe and the United States.

Prideaux said an effective vaccine was needed to provide a viable alternative to the mass culls in Asia earlier this year.

"There is a need in Asia to have a means of controlling avian influenza," he told AFP. "It is a major problem for their industries and, therefore, if we can help countries like that in controlling the disease then there are advantages for those countries."

Prideux said the vaccine would be affordable for poorer countries.

"The virus is very simple and easy to grow and it can be delivered en masse -- it can be sprayed on chickens or put in drinking water," he said. "So it's really a very appropriate technology for mass vaccination at a very cheap level."

Prideux said he was confident the genetically-modified virus would not enter the food chain through chickens.

"The virus can't replicate in humans so there is no chance of the virus replicating in non-intended species," he said.

Although the vaccine was being developed for the H5N1 virus, it could be modified for other strains of bird flu.

The CSIRO hoped to know by the end of the year whether the vaccine would work.