WordNet sense 1 (a local infection induced in humans by inoculation with the virus causing cowpox in order to confer resistance to smallpox; normally lasts three weeks and leaves a pitted scar):

vaccina, variola vaccina, variola vaccine, variola vaccinia

WordNet sense 2 (a viral disease of cattle causing a mild skin disease affecting the udder; formerly used to inoculate humans against smallpox):

cowpox