- "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.
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- 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.
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- 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.
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- Why should we expect that the new deadly highly pathogenic
avian influenza won't get out via similar route, lab accident?
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- 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...
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- Patricia Doyle
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-
- 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.
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- 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.
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- "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."
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- 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."
-
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- 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.
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- 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.
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- Masks Or Hoods
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- 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."
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- http://www.newscientist.com/news/news.jsp?id=ns99994713
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- 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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