What is smallpox?

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.

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