We may have to resurrect cowpox and horsepox!
https://www.princeton.edu/~achaney/tmve/wiki100k/docs/Cowpox.html
Do cows and horses still get the pox?
They use cow pox to immunize against small pox. The guys on their first tour got about 3 “jabs.” Since I had been previously immunized I got around 21.
If small pox is wiped out why did I have to get immunized?