Yes, but that was done by vaccinating everyone and thus breaking the cycle of transmission. Smallpox has no animal hosts (lots of mammalian species have their own version instead), so after no humans were able to get it, the disease died out. If you got it today somehow, they'd pump you full of antiviral drugs and hope for the best, but they wouldn't be able to actually end the infection, as the word "cure" would suggest.
