vaccinia

1. See cowpox.
2. The usually mild, cutaneous and sometimes systemic reaction in individuals who have been inoculated with smallpox vaccine.

[New Latin vaccīnia, from Latin vaccīnus, of cows. See vaccine.]

1. See cowpox.
2. An infection induced in humans by inoculation with the vaccinia virus in order to confer resistance to smallpox; it is usually limited to the site of inoculation. Also called primary reaction.

Pertaining to or characteristic of vaccinia.

The noun has one meaning:

Meaning #1: a viral disease of cattle causing a mild skin disease affecting the udder; formerly used to inoculate humans against smallpox
  Synonym: cowpox