cowpox

Cowpox is an infectious disease caused by Cowpox virus (CPXV). It presents with large blisters in the skin, a fever and swollen glands, historically typically following contact with an infected cow, though in the last several decades more often (though overall rarely) from infected cats. The hands and face are most frequently affected and the spots are generally very painful.

The virus, part of the genus Orthopoxvirus, is closely related to Vaccinia virus. The virus is zoonotic, meaning that it is transferable between species, such as from cat to human. The transferral of the disease was first observed in dairy workers who touched the udders of infected cows and consequently developed the signature pustules on their hands. Cowpox is more commonly found in animals other than bovines, such as rodents. Cowpox is similar to, but much milder than, the highly contagious and often deadly smallpox disease. Its close resemblance to the mild form of smallpox and the observation that dairy farmers were immune to smallpox inspired the modern smallpox vaccine, created and administered by English physician Edward Jenner.