A scientist funded by the US government has deliberately created an extremely deadly form of mousepox, a relative of the smallpox virus, through genetic engineering. The new virus kills all mice even if they have been given antiviral drugs as well as a vaccine that would normally protect them. The work has not stopped there. The cowpox virus, which infects a range of animals including humans, has been genetically altered in a similar way. The new virus, which is about to be tested on animals, should be lethal only to mice, Mark Buller of the University of St Louis told...