What is smallpox?

an acute contagious viral disease, with fever and pustules usually leaving permanent scars. It was effectively eradicated through vaccination by 1979.

It's a highly contagious infectious disease that is cause by the variola virus, individuals will develop a fever and a progressive skin rash, 3 out of 10 people who have it die and those who survive will have permanent scars in the face or even left blind.