Thanks to the success of vaccination, smallpox was eradicated. No cases of naturally-occurring smallpox have happened since 1977. The last natural outbreak of smallpox in the United States occurred in 1949.
Before smallpox was eradicated, it was a serious infectious disease caused by the variola virus. It was spread from person to person. Symptoms included fever and a distinctive, progressive skin rash.
Most people with smallpox recovered, but about 3 out of every 10 people with the disease died. Many smallpox survivors have permanent scars over large areas of their body, especially their faces. Some are left blind.
Smallpox research in the United States continues and focuses on the development of vaccines, drugs, and diagnostic tests to protect people against smallpox in the event that it is used as an agent of bioterrorism.