Friday, June 22, 2012

Influenza: Five questions on H5N1

21 June 2012

Scientists now know that the deadly bird flu virus is capable of causing a human pandemic. That makes tackling the remaining unknowns all the more urgent.

The biology of the H5N1 avian influenza virus is rife with paradoxes. The virus is widespread, but hard to detect. It kills more than half of the people known to be infected, but thousands of those exposed have no apparent problems. It seems to be just a few mutations away from gaining the ability to spread from person to person, but despite more than 16 years of fast-paced evolution, it has failed to do so.

This week saw the publication of the second of two papers identifying mutations that give H5N1 the ability to spread through the air between ferrets. The papers, the latest1 from a group led by Ron Fouchier at the Erasmus Medical Center in Rotterdam, the Netherlands, and the earlier one2 by Yoshihiro Kawaoka at the University of Wisconsin-Madison and his colleagues, have been controversial because they offer what some see as a recipe for disaster — that they increase the risk of accidental or intentional release of a deadly human pathogen. But what is most unsettling about them, say many in the flu community, is the evidence they provide that the wild virus could spark a pandemic on its own. That threat makes the outstanding scientific mysteries about this tiny RNA virus — its genome just 14,000 letters long — even more pressing. Here are five of the biggest puzzles, and what researchers are doing to solve them.

-continued, click on Title for full article -

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