Australian scientists today urged a strengthening in the provisions of the global Biological Weapons Convention, in the light of an important discovery about how disease-causing viruses may be made more deadly.
The discovery, which has been foreshadowed by a number of research groups worldwide, was made by the Co-operative Research Centre for the Biological Control of Pest Animals Canberra, as part of work to develop a biological contraceptive which would halt mouse and rat plagues and the damage they cause to the global food supply.
Researchers at the CRC found that the insertion of a particular gene affecting immunity in the mousepox virus made it deadly for breeds of laboratory mice normally resistant to the disease. They also found it made vaccines for mice against mousepox less effective.
Mousepox virus does not infect humans or pose any threat to them, but the scientists are concerned that if the technique were to be adopted by biowarfare researchers it could be used to strengthen biological weapons based on viruses which do affect humans.
"This work was carried out for completely humanitarian motives. Our aim is to counter the enormous damage and human suffering which rodents cause by devouring a major part of the global grain harvest, especially in developing countries and in Australia," CRC director Dr Bob Seamark said.
"In the course of science you sometimes make unexpected discoveries - penicillin is one example.
"In this case, we've found that certain changes to a mouse virus can render it more lethal and harder to immunise against.
"The best protection against any misuse of this technique was to issue a worldwide warning. We also want researchers to use this new knowledge to help design better vaccines."
There is a need to strengthen the global Biological Weapons Convention to take account of the discovery, according to Dr Annabelle Duncan, the Chief of CSIRO Molecular Science and former deputy head of a United Nations team that investigated the development of biowarfare agents in Iraq following the Gulf War.
"Discoveries such as this are being made all the time," she says. "The important thing is to ensure they are used for good - not for destructive purposes. That is why we urge awareness and vigilance."
A report on the discovery will be published in the Journal of Virology in its February issue. The CRC researchers feel that informing the public, governments and the world scientific community is the best way to prevent misuse of such discoveries.
The Pest Animal Control CRC uses biotechnology to develop novel fertility control methods for pest animals such as mice, rabbits and foxes.
The CRC is a research collaboration of The Australian National University, CSIRO, the University of Adelaide, the University of Sydney, the University of Western Australia, the WA Department of Conservation and Land Management and the WA Agriculture Protection Board.
CRC scientists are experimenting with the use of various viruses to deliver an antigen to the pest animal which causes an immune response to its own reproductive cells. This is known as immuno-contraception.
The goal is to suppress the plagues of mice and rats which destroy billions of dollars worth of the world grain harvest both in farmer's fields and in grain storages and spread human diseases.
In this particular experiment they modified a mousepox virus to include the gene for a substance called interleukin-4 which affects the immune system. The aim was to boost the level of the animal's immune response to block reproduction.
They found that the extra gene also had the effect of suppressing part of the mouse's immune system which deals with viruses - the cell-mediated response - with the result that lab mice normally resistant to the virus died. Furthermore it reduced the efficacy of vaccines used to protect them by about half.
The research was carried out under strict conditions of biological and physical security at the Australian National University.
The Deputy Vice-Chancellor of The Australian National University, Professor John Richards, said that ANU, like all Australian research institutions, has processes to ensure the integrity of research. "It is also important to capture unexpected research outcomes for the benefit of humanity. The knowledge gained from this particular discovery alerts us to previously unknown, yet significant, implications," he said.