And I'm sorry, but the conclusions of this account (that our vaccine will be effective against any Soviet smallpox virus the terrorists can get their hands on, etc.) don't seem logical to me. According to Ken Alibek (Alibekov), who in essence, ran the Soviet bioweapons arm for several years in the late 80's, the Soviets were working on shortening the incubation period, among other things. They may well have developed a much more sophisticated smallpox variant than what was accidentally unleashed in the the above 1971(?) incident. Alibek's book is a really good read.