Pronunciation: (vak-sin'ē-u), [key]
1. a variant of the cowpox virus that became established in vaccines derived from cowpox-inoculated humans.
2. Pathol.an acute infection caused by inoculation with vaccinia virus as a prophylactic against smallpox, characterized by localized pustular eruptions.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.