Vaccine

(yak' -sen). The occurring within the eruptive vesicle of cowpox. V., Bovine, that derived from the vesicles of heifers. V.farm, a farm upon which vaccine-virus is systematically produced and collected. V., Humanized, that from vaccinal vesicles of man. V., Lichen, the most common eruption consequent upon vaccination. It may be either papular, papulo-vesicular, or pustular, and very rarely bullous. It appears between the fourth and the eighteenth day, most frequently on the eighth; begins on the arms usually, though it may commence on the face, neck, or trunk, and appears in succe ive crops covering the greater portion of the body. The papules are acuminate, pin's-point sized, and bright-red; usually discrete, but they may coalesce into patches. The rash lasts from a few days to a week or two. See Vaccine. V. -point, a slip of quill or bone coated at one end with vaccine-lymph. V. -virus, the same prepared for use in vaccination.