Killer virus ( 10 January 2001)

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http://www.newscientist.com/news/news.jsp?id=ns9999311

 

http://www.newscientist.com/news/news.jsp?id=ns9999311

The World's No.1 Science & Technology News Service

 

Killer virus

 

19:00 10 January 01

 

A virus that kills every one of its victims, by wiping

out part of their immune system, has been accidentally

created by an Australian research team. The virus, a

modified mousepox, does not affect humans, but it is

closely related to smallpox, raising fears that the

technology could be used in biowarfare.

 

The discovery highlights a growing problem. How do you

stop terrorists taking legitimate research and

adapting it for their own nefarious purposes?

 

The Australian researchers had no intention of

producing a killer virus. They were merely trying to

make a mouse contraceptive vaccine for pest control.

" But it's a good way to show how to alter smallpox to

make it more virulent, " says Ken Alibek, former

second-in-command of the civilian branch of the Soviet

germ-warfare programme.

 

Ron Jackson of CSIRO's wildlife division and Ian

Ramshaw at the Australian National University, both in

Canberra, inserted into a mousepox virus a gene that

creates large amounts of interleukin 4. IL-4 is a

molecule that occurs naturally in the body. As part of

a study aimed at creating a contraceptive vaccine,

they were trying to stimulate antibodies against mouse

eggs, which would make the animals infertile. The

mousepox virus was merely a vehicle for transporting

the egg proteins into mice to trigger an antibody

response. The researchers added the gene for IL-4 to

boost antibody production. The surprise was that it

totally suppressed the " cell-mediated response " --the

arm of the immune system that combats viral infection.

 

Mousepox normally causes only mild symptoms in the

type of mice used in the study, but with the IL-4 gene

added it wiped out all the animals in nine days. " It

would be safe to assume that if some idiot did put

human IL-4 into human smallpox they'd increase the

lethality quite dramatically, " says Jackson. " Seeing

the consequences of what happened in the mice, I

wouldn't be the one who'd want to do the experiment. "

 

To make matters worse, the engineered virus also

appears unnaturally resistant to attempts to vaccinate

the mice. A vaccine that would normally protect mouse

strains that are susceptible to the virus only worked

in half the mice exposed to the killer version. " It's

surprising how very, very bad the virus is, " says Ann

Hill, a vaccine researcher from Oregon Health Sciences

University in Portland. If bioterrorists created a

human version of the virus, vaccination programmes

would be of limited use.

 

Alibek, who now works on developing novel treatments

for anthrax for the defence contractor Hadron in

Virginia, says this highlights the drawback of working

on vaccines against bioweapons rather than treatments.

" I'd say any vaccine could be overcome by one or

another genetically engineered virus or bacterium, " he

says.

 

Is it possible that research into new vaccines against

cancer and other diseases could inadvertently create

lethal human viruses? Many of the most promising

modern vaccines depend on viruses to transport genes

into the body, and contain genes that directly alter

the immune response. But researchers have not been too

concerned because the evidence until now suggested

that changes in the genetic make-up of viruses

invariably makes them less virulent, not more. One way

to reduce the risk, says Gary Nabel of the National

Institutes of Health, is to use only viruses that

cannot replicate. " There are some

replication-competent [viral vaccines] around, but

there is increasing concern about their use, " he says.

 

Defence experts are also worried about preserving the

freedom to publish medical findings while trying to

stop the information falling into the wrong hands.

According to D. A. Henderson, a former US presidential

adviser, and director of the Center for Civilian

Biodefense Studies at Johns Hopkins University in

Baltimore, what are effectively blueprints for making

microorganisms more harmful regularly appear in

unclassified journals. " I can't for the life of me

figure out how we are going to deal with this, " he

says.

 

The Australian researchers consulted their country's

Department of Defence before submitting the work for

publication, and only decided to go ahead after

considerable thought. A report will appear in a

February issue of the Journal of Virology. " We wanted

to warn the general population that this potentially

dangerous technology is available, " says Jackson. " We

wanted to make it clear to the scientific community

that they should be careful, that it is not too

difficult to create severe organisms. "

 

 

Rachel Nowak, Melbourne