Yes, vaccine is derived from word for cow. From a Biology class when school actually taught: Smallpox was doing a number on Europe. Gentleman named Edward Jenner found those who previously had cox pox were not getting sick. Took goo from cox pox sores, opened vein in healthy patients to push in goo (no hypodermic needles invented yet) and ta da, cox pox exposure ramped up immune system to defend against small pox exposure. This bit here may help more: https://www.historyofvaccines.org/timeline/all