Paris: Scientists who created a mutant virus to explore a key aspect of influenza published their research today after a four-month storm that brewed fears of bioterrorism and accusations of censorship.
The controversy began in December when teams in the United States and the Netherlands separately said they had engineered a hybrid virus in high-security labs.
Their goal was to understand how a highly lethal strain of flu which spreads among birds but is hard to transmit to mammals could mutate into a variant that is contagious among humans.
A 23-member expert panel that advises the US government called for manuscript changes before the work could be published in a journal, the traditional arena for displaying and discussing scientific work.
It feared that full disclosure could help a rogue state or bioterror group make a virus against which no-one would be immune.
But some scientists lashed the recommendation, saying it was an attempt to censor or stifle scientific discourse.
Two journals put the papers on hold while they consulted the researchers and the panel, the National Science Advisory Board for Biosecurity (NSABB).
Today, the British journal Nature finally published one of the studies, conducted by a team led by Yoshihiro Kawaoka at the University of Wisconsin.
"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.