* Controversial research sparked previous security fears
* Flu experts say it is critical to prepare for threat
* New H7N9 bird flu strain has killed 43 people so far
* Outbreak currently controlled, may return in autumn
By Kate Kelland, Health and Science Correspondent
LONDON, Aug 7 Scientists are to create mutant
forms of the H7N9 bird flu virus that has emerged in China so
they can gauge the risk of it becoming a lethal human pandemic.
The genetic modification work will to result in highly
transmissible and deadly forms of H7N9 being made in several
high security laboratories around the world, but it is vital to
prepare for the threat, the scientists say.
The new bird flu virus, which was unknown in humans until
February, has already infected at least 133 people in China and
Taiwan, killing 43 of them, according to the latest World Health
Organization (WHO) data.
Announcing plans to start the controversial experiments,
leading virologists Ron Fouchier and Yoshihiro Kawaoka said
H7N9's pandemic risk would rise "exponentially" if it gained the
ability to spread easily among people.
And the only way to find out how likely that is, and how
many genetic changes would need to take place before it could
happen, is to engineer those mutations in laboratory conditions
and test the virus's potential using animal models, they said.
"It's clear this H7N9 virus has some hallmarks of pandemic
viruses, and it's also clear it is still missing at least one or
two of the hallmarks we've seen in the pandemic viruses of the
last century," Fouchier told Reuters in a telephone interview.
"So the most logical step forward is to put in those
(missing) mutations first."
Writing in the journals Nature and Science on behalf of 22
scientists who will carry out various aspects of the H7N9 work,
Fouchier said because the risk of a pandemic caused by a bird
flu virus exists in nature, it was critical for risk-mitigation
plans to study the likely mutations that could make that happen.
This kind of science is known as "gain of function" (GOF)
research. It aims to identify combinations of genetic mutations
that allow an animal virus to jump to humans and spread easily.
By finding the mutations needed, researchers and health
authorities can better assess how likely it is that a new virus
could become dangerous and if so, how soon they should begin
developing drugs, vaccines and other scientific defences.
Yet such work is highly controversial. It has fuelled an
international row in the past two years after it was carried out
on another threatening bird flu virus called H5N1.
When Fouchier, of the Erasmus Medical Centre in Rotterdam,
The Netherlands, and Kawaoka, at the University of Wisconsin in
the United States, announced in late 2011 they had found how to
make H5N1 into a form that could spread between mammals, the
U.S. National Science Advisory Board for Biosecurity (NSABB) was
so alarmed that it took the unprecedented step of trying to
censor publication of the studies.
The NSABB said it feared details of the work could fall into
the wrong hands and be used for bioterrorism. A year-long
moratorium on such research followed while the World Health
Organisation, U.S. security advisers and international flu
researchers sought ways to ensure the highest safety controls.
The laboratory Fouchier will be working in is known as a
BSL3 Enhanced lab (Bio-Safety Level 3), the highest level of
biosecurity that can be achieved in academic research.
"Nature is the biggest threat to us, not what we do in the
lab. What we do in the lab is under very intense biosecurity
measures," he said. "There are layers upon layers of layers of
biosafety measures such that if one layer might break there are
additional layers to prevent this virus ever coming out."
Fouchier conceded that GOF research has been "under fire"
recently. "One of the accusations against the flu community was
that we were not transparent enough about what experiments were
being done, and why and how they were being done," he said.
"We're trying to pre-empt such accusations this time."
The H7N9 bird flu outbreak currently appears under control
with only 3 new human cases in May after 87 in April and 30 in
March. Experts say this is largely thanks to the closure of many
live poultry markets and because of warmer weather.
Yet as winter approaches in China, many experts believe H7N9
could re-emerge, meaning the threat of a pandemic looms if it
mutates to become easily transmissible between people.
The first scientific analysis of probable human-to-human
transmission of H7N9 raised concern about its pandemic potential
and prompted scientists James Rudge and Richard Coker of the
London School of Hygiene and Tropical Medicine to warn: "The
threat posed by H7N9 has by no means passed."
Fouchier and colleagues said they hope to unravel the
molecular processes behind H7N9 by manipulating its genetic
material to increase virulence or induce drug resistance.
Wendy Barclay, an Imperial College London flu expert, said
it would be ludicrous to shy away from such studies. "This type
of work is like fitting glasses for someone who can't see well,"
she said. "Without the glasses the vision is blurred and
uncertain, with them you can focus on the world and deal with it
a lot more easily."
(Reporting by Kate Kelland; editing by David Evans)