Smallpox is a highly contagious and deadly disease that can give you flu-like symptoms and leave you with disfiguring scars. About one in three people that contract smallpox die from it. You can acquire smallpox if you are in close proximity with someone who has it as the virus spreads easily through saliva. If you are infected with smallpox symptoms will develop after 10 to 12 days. You might come down with fever, aches, a rash, and fatigue. No treatment is available for smallpox, but you can control the fever and any pain with IV fluids and medicines. The last known case of smallpox was from 1977, thanks to global immunization. Because of its highly contagious and severe nature, scientists are not able to easily study smallpox.