rescue it into live virus – use it to make live virus

Smallpox virus is almost extinct. Stocks of it are held only by the Americans and the Russians. This would be a good project for terrorists or totalitarian governments looking for an alternative to making nuclear weapons. In theory, it is remarkably easy. First, they synthesise a small amount of the smallpox virus DNA chemically. Then, they infect cells with another poxvirus and shortly afterwards transfect the synthetic smallpox virus DNA into the infected cells. As the infection proceeds, the poxvirus replicates its own DNA and makes new virus particles as usual. This DNA is packaged into the particles to complete the replication process. However, at the same time, the synthetic smallpox virus DNA is also recognised by the genetic system of the other poxvirus. So the synthetic smallpox virus DNA is also replicated and smallpox virus particles are made, based on the synthetic smallpox virus DNA, but using the genetic mechanisms of the other poxvirus. The newly made smallpox virus DNA is packaged into the newly made smallpox virus particles, which results in live, that is infectious, smallpox virus.

Here is an introduction to the problem:

http://news.bbc.co.uk/2/hi/2122619.stm

Here is an article about it:

http://www.plospathogens.org/article/info:doi/10.1371/journa...

And here is how to do it:

http://jvi.asm.org/cgi/content/full/77/13/7281