“I thought all samples of smallpox virus had been destroyed.”
The Soviets and the US kept small samples to study. Some of the Soviet stuff got out apparently.
Here is the scariest article I have ever read: The Demon in the Freezer.
http://cryptome.org/smallpox-wmd.htm
>> “Some of the Soviet stuff got out apparently” <<
.
More likely some of the US ‘stuff.’
That article gave me a warm fuzzy feeling all over. Not.