14 Mai 1796 Jahr - 4 May 1796: Edward Jenner tests his hypothesis: People that have had
cowpox would be immune to smallpox. He observed this
because he saw that many milk maids were immune to smallpox.
He proved his hypothesis by inoculating (vaccinating) an eight year old boy.
Later, he was exposed to variolous material, but no infection followed.
He contributed because he subsequently showed how this worked
and finally vaccination was accepted and variolation was later banned.