vac'cine

i. Relating to vaccina in the cow or man. 2. The virus of cowpox, used by inoculation to confer immunity against smallpox; what is now employed is serum from the vesicles of the disease in a heifer, but formerly the scab of the dried pustule, taken from the animal or from man, was used. The modified and attenuated virus of any disease, incapable of producing a severe infection, but affording protection, when inoculated, against the action of the unmodified virus. 4. An emulsion of dead cultures of specific bacteria in saline solution, employed hypodermically in opsonic therapy. a'queous v., a v. having physiological salt solution as the vehicle, distinguished from lipovao-