My recollection is that the smallpox vaccine was NOT based on a mutation of the small pox virus. It was instead based upon a related virus (cox pox) (but was not simply mutated in the early 1900's. The cow pox virus existed for a long-time prior.
Vaccinia does not cause any serious complication in humans, but at the same time confers immunity to small pox because of the smilarity of the antibodies between the two.
Well, I think the way most physicians and scientists would think of this is different. The issue is NOT the similarity of the antibodies. The issue IS the similarity in the protein coating of both the vaccine virus and the small pox wild-type virus.
So, while THE REAL smalpox virus may be found only in the US and the USSR, vaccinia is still available for the production of the smallpox vaccine.
Correct! However, with molecular technologies you could theoretically alter the proteinaceous coating of the virus in order to defeat the vaccine's utility. I think that is probably out of the capability of the Taliban.