The U.S. develops a lethal new virus through genetic engineering

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.