Scientists develop new basis for H5N1 vaccine - WHO

GENEVA (Reuters) - Scientists have used bird flu virus samples from Egypt to develop a new basis for a vaccine against the toxic H5N1 strain that continues to circulate, the World Health Organisation said on Thursday.

Avian influenza kills about half the people it infects, but unlike the quickly circulating H1N1 flu virus has not been shown to pass easily between humans to date.

In a statement, the WHO said the seed virus was developed at the U.S. Centers for Disease Control and Prevention in Atlanta "thanks to the ministry of health and population of Egypt for providing virus specimens."

"This recombinant vaccine virus is available for distribution," it said.

"Institutions, companies and others interested in pandemic vaccine development who wish to receive these candidate vaccine viruses should contact either the WHO Global Influenza Programme ... or the Centers for Disease Control and Prevention."

Vaccine makers including Novartis have already been working on immunisations against the H5N1 bird flu strain, which experts fear could trigger a deadly pandemic if it mutates and starts spreading easily between people.

Avian influenza has been regularly causing disease in birds -- 250 outbreaks in February alone in Bangladesh, China, Egypt, India, Indonesia, Laos, Nepal and Vietnam, according to the U.N. Food and Agriculture Organisation.

It has killed 261 people out of 424 infected since 2003, according to the WHO. By contrast, the recently-discovered H1N1 strain that has also put the world on pandemic alert has infected more than 13,000 people but killed just 95, according to officially confirmed figures from the WHO.

Scientists need fresh samples of the H5N1 virus as it continues to spread, as it has been doing in Egypt, so that any vaccines made against the flu strain match its latest form.