Cowpox is a disease of the skin that's caused by a virus known as the Cowpox virus. The pox is related to the vaccinia virus, and got its name from dairymaids touching the udders of infected cows. The ailment manifests itself in the form of red blisters and is transmitted by touch from infected animals to humans. When the patient recovers from cowpox, the person is immune to smallpox. The cowpox virus was used to perform the first successful vaccination against a disease, smallpox, which is cau… (More on Cowpox)