A non-pathogenic virus that is believed to be a (modified) form of the virus that causes cowpox. Vaccinia readily accepts genes (inserted into its genome via genetic engineering) from pathogenic viruses so it can be used to make vaccines that do not possess the risk inherent in attenuated-virus vaccines (i.e., that the attenuated virus “revives” and causes disease). Such genetically engineered vaccinia codes for (presents) the proteins of the pathogenic virus on its surface, which activates the immune system (e.g., of vaccinated animal) to produce antibodies against that pathogenic virus.
Another term for cowpox, a disease in which vesicles form on the udders and teats of cows, due to the same virus as is responsible for smallpox in humans. It is also the term used to describe the reaction to smallpox vaccination.
A contagious disease of cattle, produced in humans by inoculation with cowpox virus to confer immunity against smallpox. Papules form about the third day after vaccination, changing to umbilicated vesicles about the fifth day, and at the end of the first week becoming umbilicated pustules surrounded by red areolae. They dry and form scabs, which fall off about the second week, leaving a white pitted depression.
Cowpox, an infectious bovine illness marked by vesicles and sores on the skin, typically manifesting near the teats and udders. Humans can contract this disease by contact with infected cows or through vaccination. It provides immunity to smallpox.