By Agence France-Presse
Wednesday, May 2, 2012 15:36 EDT

“The essential scientific elements (in the original manuscript) were unchanged,” the journal said, adding it was publishing the paper after receiving “several independent pieces of biosecurity advice”.

Kawaoka’s team delved into the H5N1 strain of avian flu, which caused a health scare in Hong Kong in 1997 and still surfaces sporadically today.

H5N1 spreads easily among poultry and wild birds but is hard to transmit to humans. When it does, it is brutal, killing more than one infected person in two.

The team took a key gene, known as haemagluttinin or HA, from the H5N1 virus and added a mutation that made it more compatible with human respiratory cells.

They then took a strain of H1N1 flu — the virus that caused a pandemic among humans in 2009 but proved to be no more lethal than ordinary seasonal flu — and replaced its HA gene with the engineered one.

The next step was to test the “H5/H1 hybrid” on six ferrets, a mammal deemed an excellent model for testing flu because its respiratory system is so similar to that of humans.

The infected ferrets passed on the virus to others in respiratory droplets, thus proving that the new virus could be spread through coughs and sneezes.

But none of the animals died, something that remains to be explained, said the researchers.

The findings shed light on the genetic borrowings that help a virus gain in contagiousness, they said. This risk is all too present in nature, especially in pigs, which can mix avian, human and porcine viruses.

The work will help alert health watchdogs to emerging viral threats and provide vaccine engineers with potential targets, they argued.

Nature showed journalists a report from “a bio-defence agency outside the US”, which it declined to name, that said the benefits of publication outweighed the risks.

“This information could be used by an aggressor and shows one of the building blocks for the development of a potential BW [biowarfare] weapon,” the report said.

Entire article here:   http://www.rawstory.com/rs/2012/05/02/controversial-mutant-virus-st...