* Egyptian samples used for seed virus for H5N1 vaccine
* Avian influenza far more toxic than new swine flu strain
* WHO stresses need for continued sharing of virus specimens
(Adds details, background)
By Laura MacInnis
GENEVA, May 28 (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.
The WHO said the candidate 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 in a statement on its website.
“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.”
Pharmaceutical companies including Novartis are already working on vaccines against H5N1 bird flu, which has killed or forced the culling of more than 300 million birds since 2003 as it spread to 61 countries in Asia, the Middle East and Africa.
While eclipsed on the headlines by the highly contagious H1N1 strain, which proved deadly in its North American epicentre but has caused mild symptoms as it spread, the WHO stressed it was important to remember the risks posed by avian influenza.
The U.N.’s Food and Agriculture Organisation reported 250 outbreaks of H5N1 in birds in February alone -- in Bangladesh, China, Egypt, India, Indonesia, Laos, Nepal and Vietnam.
Avian influenza has killed 261 people out of 424 infected since 2003. By contrast, the H1N1 strain, commonly known as swine flu and which has put the world on pandemic alert, has infected more than 13,000 people but killed just 95, according to WHO figures.
Its statement on Thursday said flu experts were continuing to monitor the evolution of avian influenza and other flu viruses and stressed the need for countries to keep providing samples of identified strains.
“Countries are encouraged to share with WHO their specimens and/or isolates, both from humans and animals, for their inclusion in the WHO H5N1 vaccine virus development and selection process, in addition to other activities of public health significance,” it said.
Virus sharing is a sensitive topic for developing countries such as Indonesia, who have bristled at the idea of companies using their biological material to manufacture and patent vaccines that are then sold at unaffordable prices.
WHO Director-General Margaret Chan, who raised the United Nations agency’s pandemic alert to 5 out of 6 in response to the fast spread of swine flu, is trying to broker an international agreement on the sharing of virus samples by January 2010.
She has called on countries to do all they can to ensure fresh samples of both H5N1 and the new H1N1 strains reach the pharmaceutical community so that their vaccines can offer immunity against the latest forms of the viruses.
The WHO’s statement did not include new guidance on the H1N1 virus or vaccines to fight it. WHO officials have said they would offer recommendations “during the summer” about how many pandemic vaccines focused on that strain may needed, depending on whether it continues to cause mild effects as its spreads.
British scientists have produced a strain of H1N1 flu virus which could be used for largescale production of a vaccine, should it go ahead.
That strain is being made available to the pharmaceutical industry and other flu laboratories, Britain's Health Protection Agency said on Thursday, describing it as "a crucial step towards large scale production of a vaccine against swine flu". (For more Reuters swine flu coverage, please click here: here )