A scarring and often deadly disease passed from person to person caused by the smallpox virus.

Smallpox is a serious viral disease that can cause scarring and death. Smallpox was wiped out worldwide by 1980. It's no longer found naturally in the world. But samples of the virus have been kept in labs for use in research.

Symptoms of smallpox usually show up about 12 to 14 days after a person is in contact with the virus. These might include flu-like symptoms such as fever, tiredness and muscle aches. Then flat spots appear on the body. They become blisters before they scab and fall off and can leave scars.

New antiviral medicines might treat smallpox, but they haven't been tested in people with the disease. A vaccine can prevent it. But the vaccine isn't given regularly because the risk of getting smallpox is so low.