Inoculation with a vaccine, in order to protect from a particular disease or strain of disease.
Etymology: From vaccinia, a cowpox infection. Ultimately from Latin vacca (“ cow ” ). The term was coined by Edward Jenner (1749-1823) who infected people with weakened cowpox viruses (Vaccinia), to immunise them against the disease. It is now known that vaccinia and cow pox are separate conditions, but at the time of Jenner, they were considered the same condition.