Experts warn of danger that the
new viral strains created by mixing bird-flu virus with human influenza
could escape from the laboratory to cause a global pandemic killing
millions of people.
Senior scientists have criticized the
“appalling irresponsibility” of researchers in China who have
deliberately created new strains of influenza virus in a veterinary
laboratory.
They warned there is a danger that the
new viral strains created by mixing bird-flu virus with human influenza
could escape from the laboratory to cause a global pandemic killing
millions of people.
Lord May of Oxford, a former government
chief scientist and past president of the Royal Society, denounced the
study published today in the journal Science as doing nothing to further
the understanding and prevention of flu pandemics.
“They claim they are doing this to help
develop vaccines and such like. In fact the real reason is that they are
driven by blind ambition with no common sense whatsoever,” Lord May
told The Independent.
“The record of containment in labs like
this is not reassuring. They are taking it upon themselves to create
human-to-human transmission of very dangerous viruses. It’s appallingly
irresponsible,” he said.
The controversial study into viral mixing
was carried out by a team led by Professor Hualan Chen, director of
China’s National Avian Influenza Reference Laboratory at Harbin
Veterinary Research Institute.
Professor Chen and her colleagues
deliberately mixed the H5N1 bird-flu virus, which is highly lethal but
not easily transmitted between people, with a 2009 strain of H1N1 flu
virus, which is very infectious to humans.
When flu viruses come together by
infecting the same cell they can swap genetic material and produce
“hybrids” through the re-assortment of genes. The researchers were
trying to emulate what happens in nature when animals such as pigs are
co-infected with two different strains of virus, Professor Chen said.
“The studies demonstrated that H5N1
viruses have the potential to acquire mammalian transmissibility by
re-assortment with the human influenza viruses,” Professor Chen said in
an email.
“This tells us that high attention should
be paid to monitor the emergence of such mammalian-transmissible virus
in nature to prevent a possible pandemic caused by H5N1 virus,” she
said.
“It is difficult to say how easy this
will happen, but since the H5N1 and 2009/H1N1 viruses are widely
existing in nature, they may have a chance to re-assort,” she added.
The study, which was carried out in a
laboratory with the second highest security level to prevent accidental
escape, resulted in 127 different viral hybrids between H5N1 and H1N1,
five of which were able to pass by airborne transmission between
laboratory guinea pigs.
Professor Simon Wain-Hobson, an eminent
virologist at the Pasteur Institute in Paris, said it is very likely
that some or all of these hybrids could pass easily between humans and
possess some or all of the highly lethal characteristics of H5N1
bird-flu.
“Nobody can extrapolate to humans except
to conclude that the five viruses would probably transmit reasonable
well between humans,” Professor Wain-Hobson said.
“We don’t know the pathogenicity
[lethality] in man and hopefully we will never know. But if the case
fatality rate was between 0.1 and 20 per cent, and a pandemic affected
500 million people, you could estimate anything between 500,000 and 100
million deaths,” he said.
“It’s a fabulous piece of virology by the
Chinese group and it’s very impressive, but they haven’t been thinking
clearly about what they are doing. It’s very worrying,” Professor
Wain-Hobson said.
“The virological basis of this work is
not strong. It is of no use for vaccine development and the benefit in
terms of surveillance for new flu viruses is oversold,” he added.
An increasing number of scientists
outside the influenza field have expressed concern over attempts to
deliberately increase the human transmissibility of the H5N1 bird-flu
virus. This is done by mutating the virus so that it can pass by
airborne droplets between laboratory ferrets, the standard “animal
model” of human influenza.
Two previous studies, by Ron Fouchier of
Erasmus Medical Centre in Rotterdam and Yoshihiro Kawaoka of the
University of Wisconsin, Madison, caused uproar in 2011 when it emerged
that they had created airborne versions of H5N1 that could be passed
between ferrets.
The criticism led to researchers to
impose a voluntary moratorium on their H5N1 research, banning
transmission studies using ferrets. However they decided to lift the ban
earlier this year, arguing that they have now consulted widely with
health organisations and the public over safety concerns.
However, other scientists have criticized the decision to lift the moratorium.
Source:
www.independent.co.uk
http://worldtruth.tv
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