| September
11, 2003
Contact: Stephen M. Apatow
Director of Research
& Development
Humanitarian Resource
Institute Legal Resource Center
Biodefense Reference
Library
Eastern USA: (203) 668-0282
Western USA: (775) 884-4680
Internet:
http://www.humanitarian.net/law/biodefense
Email: s.m.apatow@humanitarian.net
The topic of genetically
modified organisms (GMOs) has once again entered into widespread discussion
as per the release of the following article "Designer Diseases" published
in the New Scientist, 27 August 2003. Concerns relate to (1) the genetic
modification of a virus designed for release, replication and spread as
a form of pest control, (2) the inability to control the spread of the
agent once released into wildlife, (3) the capacity for mutation, recombination
and potential to jump species, and (4) the potential for accidental or
deliberate spread/transport to other countries.
Serious concerns relating
to this field of research entered the international spotlight in January,
2001, when Australian scientists developing a contraceptive vaccine for
controlling field mice populations sought to enhance the vaccines effectiveness
by inserting the gene for the immune regulatory protein interleukin-4 (IL-4)
into mousepox, which was being used as a carrier virus. IL-4 is a
substance that is normally produced in mice, but insertion of the IL-4
gene into the mousepox genome unexpectedly transformed the normally benign
virus into a virulent strain that shut down the immune system and killed
all the animals in the experiment. In addition to rendering mousepox
lethal in mice genetically resistant to the virus, the inserted gene made
the mousepox vaccine ineffective - the recombinant virus killed even those
mice that had previously been vaccinated. [1] Since human beings
possess the interleukin-4 gene, it is possible that inserting this gene
into a poxvirus that infects humans, such as smallpox or monkeypox, could
create a lethal strain that would be resistant to the existing smallpox
vaccine. [2]
In response to the threats
presented, the international community is seeking guidance by the World
Organization for Animal Health (OIE), Food and Agriculture Organization
of the United Nations (FAO) and World Health Organization (WHO).
References:
[1] R.J.Jackson et al. (2001),
"Expression of Mouse Interleukin-4 by a Recombinant Ectromelia Virus Supresses
Cytolytic Lymphocyte Responses and Overcomes Genetic Resistance to Mousepox,"
Journal of Virology, 75 (2001), pp. 1025-10.
[2] Tucker, Regulating Scientific
Research of Potential Relevance to Biological Warfare, Monterey Institute
of International Studies - After
9/11: Preventing Mass-Destruction Terrorism and Weapons Proliferation,
Center for Nonproliferation Studies, Occasional Paper No.8, May 2002, p.
24.
http://www.eurekalert.org/pub_releases/2003-08/ns-dd082703.php
New Scientist issue: 30
AUGUST 2003
Designer diseases
EVERY few years, a plague
of European house mice infests one of Australia's grain regions. Roads
turn into fur carpets of squashed mice. Millions of dollars' worth of grain
is eaten or spoiled. Homes and buildings are damaged. The only defence
is poison, a slow painful death for the mice, and for any other animals
that can get at the bait.
How much better it would
be to have a kinder, gentler form of pest control, one that renders female
mice infertile, preventing plagues before they start and leaving native
wildlife untouched.
And that is just what the
Pest Animal Control-Cooperative Research Centre (PAC-CRC) in Canberra hopes
it has created. Its agent could be undergoing contained field trials in
Australia within two years, and be commercially available within five.
But there's a catch. The
agent in question is a genetically modified virus designed to replicate
and spread. It is a new, man-made disease, one of several being developed
(see "On the drawing board", opposite). Once released, they will be as
hard to control as any other wildlife disease. Like natural diseases, they
could be accidentally or deliberately taken to other countries. They could
mutate or recombine with other viruses. They could jump species. The consequences
could be disastrous.
The European house mouse
may be an exotic pest in Australia, for instance, but in many countries
it is a native animal and a key part of the food chain. Nor is the mouse
virus the only "disseminating" or transmissible genetically modified organism
with the potential to spark international conflict. A team in New Zealand
is modifying a parasitic nematode to sterilise brushtail possums a devastating
pest in New Zealand but a protected species in Australia. "Once you've
let it go, you can't get it back," admits Warwick Grant, head of the team
at AgResearch in Upper Hutt. "Biological control has a chequered history.
The stakes are pretty high and you don't want to get it wrong."
Meanwhile, on a small island
in Spain, a transmissible GMO with quite a different purpose has already
been tested. It is a living vaccine that protects rabbits from myxomatosis
and calicivirus. These diseases have decimated Spanish rabbit populations,
causing consternation among hunters as well as affecting predators such
as the threatened Iberian lynx and the Spanish imperial eagle. Australian
farmers, by contrast, were only too happy when calicivirus escaped from
a research station on Wardang Island in 1995. For them, the arrival
of the Spanish virus would be a disaster, allowing rabbit populations to
boom. If the potential for international conflict is obvious, the
means of preventing it is not. None of the researchers contacted by New
Scientist knew who to consult in countries that might be adversely affected
by the transmissible GMOs they are developing, what they would do
if a country objected to the GMO, and what international laws govern the
release of such organisms.
The confusion is understandable.
Within the European Union, the European Agency for the Evaluation of Medicinal
Products must approve the commercial use of the Spanish GMO rabbit vaccine-
and it is unlikely to do so given the current European distaste for GMOs,
according to team member Juan B‡rcena of the Centre for Animal Health Research
(CISA) in Madrid.
Around the world, various
organisations have put out recommendations on the use of GMOs in general,
but only one, the World Organisation for Animal Health (OIE), is anywhere
close to exerting control over transmissible GMOs. Earlier this year, a
report from its Working Group on Wildlife Diseases again raised concerns
about these organisms. The OIE has yet to establish an official position
on the issue, but if it does, member countries would likely take notice.
But for now, PAC-CRC teams in Australia only need permission from the Office
of the Gene Technology Regulator to release a GMO. The OGTR considers a
GMO's potential impact on the environment and can consult internationally.
But it is not clear whether the OGTR has the power or the will to refuse
to allow a transmissible GMO to be released in Australia because of its
potential impact in another country. The head of the OGTR, Sue Meek, declined
to be interviewed.
"The public is not even aware
of these developments," says Robert Henzell of the Animal and Plant Control
Commission in Adelaide, South Australia. He thinks that transmissible GMOs
could be useful in places like Australia, with its vast tracts of
sparsely populated land. But the job of pest control must be done safely,
Henzell says. "We want to talk about these things before they are let go,
rather than pick up the pieces later."
Tony Peacock, head of the
PAC-CRC, argues that Australia's island status and its distance from other
countries, allied with quarantine procedures, would be enough to stop a
GMO from leaving its shores. But those barriers were not enough to stop
people illegally taking calicivirus from Australia to New Zealand in 1997.
Peacock also says that the consequences, should the mouse GMO escape, would
not necessarily be disastrous, because the speed it spreads depends on
the density of the mouse population. "The GMO is designed to avoid plaguing,
not to wipe out a population," he says.
But that is not good enough
for Henzell, who is organising a symposium on transmissible GMOs in New
Zealand later this year. One topic up for discussion there is the
development of safety measures that would help stop such organisms straying.
One tactic would be to engineer a GMO to die out after few generations.
But this runs counter to the whole idea of transmissible GMOs, which is
that by being self-sustaining they avoid the huge expense of methods like
laying bait.
Another option, says Henzell,
would be to engineer an organism so that it is activated only in the presence
of a specific chemical, such as something found only in the diet of animals
in the country where it is intended to work. Alternatively, a second transmissible
GMO that protects animals from the first could be developed for use in
non-target countries. "We ought to at least consider these things and ask
whether they are possible," says Henzell. "But there's been nothing done
so far."
And the potential for transmissible
GMOs to spread to other countries is just one of the safety issues. What
if the mouse virus- a modified mouse cytomegalovirus- jumps species and
starts infecting one of Australia's own endangered rodents, or even people?
"You can't assume that the modified virus will act like the parental strain,"
warns Adrian Gibbs, an expert on viral evolution formerly at
the Australian National University in Canberra.
So far PAC-CRC has shown
only that the mouse GMO does not infect rats, and that three species of
native rodents are immune to the unmodified virus. It is gearing
up to conduct safety experiments that will test the virus's ability to
infect a wide range of species, including some rare mouse species in the
US. The ultimate experiment will be releasing the virus. If it turns out
that PAC-CRC has got it wrong, there may be little anyone can do about
it.
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