The last
naturally occurring case of smallpox was diagnosed on 26 October 1977 (there was a death in Birmingham in 1978 but that was a lab connected infection) and the world Health Organisation certified the global eradication of smallpox in 1979.
The virus is stored in two labs, one in Russia and one in the USA.
And the milkmaids didn't get immunity from
drinking milk. Their immunity came from contracting cow pox from handling the udders of infected cows.
(You can take the woman out of the history classroom but you can't take the history classroom out of the woman
)