Cowpox

Cowpox is a viral infection that primarily affects cows and can be transmitted to humans through contact with infected animals or their tissues. In humans, it usually causes localized skin sores or blisters that heal over time. Historically, cowpox was important because it led to the development of smallpox vaccines; the cowpox virus is related to smallpox but causes milder illness. Modern vaccination against smallpox uses a virus similar to cowpox to safely trigger immunity. Cowpox is now rare, thanks to improved animal management and vaccination programs.