US study: New flu inefficient in attacking people

With swine flu continuing to spread around the world, researchers say they have found the reason it is - so far - more a series of local blazes than a wide-raging wildfire.     

The new virus, H1N1, has a protein on its surface that is not very efficient at binding with receptors in people's respiratory tracts, researchers at the Harvard University-Massachsetts Institute of Technology Division of Health Sciences and Technology report in today's edition of the journal Science.     

"While the virus is able to bind human receptors, it clearly appears to be restricted," Ram Sasisekharan, lead author of the report, said in a statement.     

But flu viruses are known to mutate rapidly, the research team noted, so this one must be watched closely in case it changes to become easier to spread.     

On June 11, the World Health Organisation declared a level 6 pandemic alert for H1N1. More than 300 people have died and more than 70,000 people have been infected, according to the WHO.     

It is currently flu season in the Southern Hemisphere and the spread of the virus in Argentina has prompted schools there to give students an early vacation and one province to declare a public health emergency.     

Yesterday, Health and Human Services Secretary Kathleen Sebelius said the US will provide 420,000 treatment courses of the anti-viral medicine Tamiflu to the Pan-American Health Organisation to fight the flu in Latin America and Caribbean.