“– smallpox has no animal reservoir. Without human incubators, the virus cannot naturally exist.
It also doesn’t stay alive on its own for long. In the past, some researchers and news outlets speculated that smallpox in the frozen graves of former victims might remain in suspended animation, ready to begin a new cycle of infection should those bodies ever be dug up and thawed. Scientists have attempted to excavate corpses in frozen graves in Alaska and Siberia that contain the remains of smallpox victims, however none of the bodies contained viable viruses. “No one feels there’s a serious chance that global warming will melt the permafrost and unleash an epidemic,” says Michael Lane, who served as director of the Centers for Disease Control’s (CDC) smallpox eradication programme from 1970 until 1981, when it was declared a success and shut down.....”
http://www.bbc.com/future/story/20140130-last-refuge-of-an-ultimate-killer
” “– smallpox has no animal reservoir. Without human incubators, the virus cannot naturally exist.”
How do the Russians and the US maintain their smallpox stocks?