But we've sequenced the DNA for all major variations, isn't it easily replicable?
You probably could sequence it, although it would be extremely hard to do as although small, smallpoxs DNA is around 180 killabases in size. Major problem with doing this coupled with the fact of making the DNA is what the hell do you package it in if you also kill off anything similar to it? Making a protein coat for the DNA which functions exactly as a viral protein coat does would be pretty much impossible with our current level of technology.
Even when the world health organisation declares the disease as extint, weapons research labs will still hold small quantities of it on ice just because its extremely easy to kill people with old diseases when the vaccinations have stopped for a few generations...
