Scientists Try To Make
Super Deadly Flu Pathogen
From Patricia Doyle, PhD
dr_p_doyle@hotmail.com
2-27-4
"They" are tweaking away. No chance for the new genetically
manipulated pathogen to leave the lab? It is playing Russian Roulette
and, eventually, a 'bullet' will exit the gun barrel.
We just went through an event I believe was a lab-escaped pathogen,
SARS. There have been countless lab accidents over the decades. Most
recently, a lab researcher was infected with Ebola when she accidently
stuck herself with a needle that contained the deadly virus. Ebola is
worked on in the HIGHEST level of security, BSL 4, yet, accidents
still happen.
There have been other incidents in which a researcher,
knowingly-infected with some dangerous pathogen did not report the
incident, i.e. until he was taken to the ER of a local hospital and
had to explain he may be infected with Sabin virus through his work.
Why should we expect that the new deadly highly pathogenic avian
influenza won't get out via similar route, lab accident?
What do we call people who do not learn by their mistakes? "Stupid."
They are risking the lives of countless millions on the planet. Then
again, that might be the sinister plan. Eliminate about one third of
the population, especially the infirmed, very young and the elderly
and save money on retirement social security checks for George Bush
and Alan Greenspan. Yes, maybe that is the plan...
Patricia Doyle
Superflu Is Being Brewed In The Lab Exclusive from New Scientist
Print Edition. After the worldwide alarm triggered by 2003's SARS
outbreak, it might seem reckless to set about creating a potentially
far more devastating virus in the lab. But that is what is being
attempted by some researchers, who argue that the dangers of doing
nothing are even greater.
We already know that the H5N1 bird flu virus ravaging poultry farms in
Asia can be lethal on the rare occasions when it infects people. Now a
team is tinkering with its genes to see if it can turn into a strain
capable of spreading from human to human. If they manage this, they
will have created a virus that could kill tens of millions if it got
out of the lab.
Many researchers say experiments like this are needed to answer
crucial questions. Why can a few animal flu viruses infect humans?
What makes the viruses deadly? And what changes, if any, would enable
them to spread from person to person and cause pandemics that might
prove far worse than that of 1918? Once we know this, they argue, we
will be better prepared for whatever nature throws at us.
Others disagree. It is not clear how much we can learn from such work,
they argue. And they point out that it is already possible to create a
vaccine by other means. The work is simply too dangerous, they say.
"I'm getting bombarded from both sides," says Ronald Atlas, head of
the Center for Deterrence of Biowarfare and Bioterrorism at the
University of Louisville in Kentucky. "Some say that this sort of
research is dangerous because of the risk of the virus escaping or
being using in bioterrorism, and others that it's good science."
Rodents And Monkeys
Some researchers refuse to discuss their plans. But Jacqueline Katz at
the US Centers for Disease Control (CDC) in Atlanta, Georgia, told New
Scientist her team is already tweaking the genes of the H5N1 bird flu
virus that killed several people in Hong Kong in 1997, and those of
the human flu virus H3N2.
She is testing the ability of the new viruses to spread by air and
cause disease in ferrets, whose susceptibility to flu appears to be
remarkably similar to ours.
Albert Osterhaus of Erasmus University in Rotterdam in the Netherlands
plans to test altered viruses on rodents and macaque monkeys. Other
groups are also considering similar experiments, he says.
If such work were to show that H5N1 could cause a human pandemic,
everything that is happening in Asia would be even more alarming,
Osterhaus argues. If, on the other hand, it failed to transform H5N1
into a highly contagious human virus, we could relax. "It becomes a
veterinary health problem, not a public health problem. That would be
an enormous relief."
Cell Cultures
But Wendy Barclay of the University of Reading in the UK, who "thought
long and hard" about trying to create a pandemic flu virus before
abandoning the idea, disagrees. "If you get a negative, how can you be
sure that you have tested every option?" she says. Health authorities
would still have to take the precaution of creating H5N1 vaccines.
Barclay concedes, however, that creating a virus that spreads in
people might tell us how real the threat is. For instance, do you need
one mutation for H5N1 to adapt to humans, or dozens?
Osterhaus is more optimistic. "Within the next decade, the whole thing
will be solved," he says. "We will know the rules." In other words,
once experts understand what the genetic sequence of any flu virus
means, they could predict which animals it can infect, how severe it
will be, and how easily it will spread.
Yet any new viruses could only be tested in human cell cultures or in
animals, not on people. None of these methods exactly reflects how flu
behaves in humans. This has led some flu experts to argue that
attempts to create a pandemic virus should be put on hold until there
is agreement on the best way of testing it.
Mix Flu Genes
And there is an even more fundamental objection to such experiments:
the processes used to create the viruses may be too artificial.
Researchers who want to see if H5N1 can be pandemic can take two
approaches.
One is to tinker with the genome of the bird flu virus to mimic
mutations that might occur naturally. This can be done precisely using
a technique called reverse genetics. The other approach is to mix bird
flu genes with those of human flu viruses, either using reverse
genetics or through random re-assortment in cells infected with both
types.
Although re-assortment sounds more natural, there is a problem.
"Re-assortments can be made very easily in the lab using cells or
animals," says flu expert Graeme Laver, formerly at the Australian
National University in Canberra. "But one of the big mysteries is that
[human] viruses that appear by reassortment are extremely rare in
nature. There is something else involved that we don't understand."
Then there is the question of safety. The worst-case scenario is that
researchers might end up engineering extremely dangerous viruses that
would never have evolved naturally.
Masks Or Hoods
In 2001, for instance, Australian researchers created a mousepox virus
far more virulent than any wild strains. This scenario is unlikely,
but not impossible, says virologist Earl Brown of the University of
Ottawa, Canada. "You could create something that is right out of
whack, but I'd be surprised."
For those reasons, several prominent flu researchers told New
Scientist that the H5N1 experiments must be done at the highest level
of containment: Biosafety Level 4, or BSL-4. But the CDC work is being
done at BSL-3Ag, an intermediate level between BSL-3 and BSL-4.
Workers wear half-suits with masks or hoods to prevent infection, for
instance, rather than full-body suits as in BSL-4.
"US Department of Agriculture guidelines specify that work with highly
pathogenic avian strains be done in BSL-3+ (also known as BSL-3Ag)
laboratories," a CDC spokeswomen says.
One of the reasons is that the H5N1 virus is regarded as a
non-contagious, treatable disease in humans. But this is not
necessarily true of all of the genetically engineered strains that
might be created. And drug supplies would quickly run out if an
escaped virus triggered a major epidemic.
New Variants A recent report by the US National Academy of Sciences
recommends a series of checks be put in place to control such
research. It says a panel of leading scientists and security experts
should be set up to regulate it.
"Some public representation is another option," says Atlas, who helped
draw up the report. At the moment, however, such experiments can be
carried out without any special consultation.
Methods like reverse genetics might also be used to create new
variants of other diseases. "You can make some pretty unusual things
new viruses that would never have existed in nature," says Barclay.
"It's not just an issue for flu."
http://www.newscientist.com/news/news.jsp?id=ns99994713
Patricia A. Doyle, PhD Please visit my "Emerging Diseases" message
board at:
http://www.clickitnews.com/ubbthreads/postlist.php?Cat=&Board=emergingdiseases
Zhan le Devlesa tai sastimasa Go with God and in Good Health
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