The announcement by a group of Australian researchers that they inadvertently had created a lethal mousepox virus during the search for a mouse contraceptive created a public stir over the potential for germ warfare. But the importance of their creation is not clear. Given a scientific knowledge of immunology, it is not surprising that the modified virus proved to be lethal; it is less clear when bioengineering will become an efficient tool for developing weapons of mass destruction.

As published in the Journal of Virology, the researchers set out to develop a contraceptive vaccine that could be used for mice. They used a well-characterized target, ZP3, a zona pellucida antigen that is only present in the ovary. To elicit an immune response, the researchers delivered ZP3 in a mousepox virus, which was chosen as the vector because it also is well characterized.