What country is smallpox most common?

Smallpox was a highly contagious disease caused by the variola virus, but it has been eradicated since 1980 due to a successful global vaccination campaign led by the World Health Organization. Therefore, there are no countries where smallpox is currently common, as the disease no longer exists in the natural environment. The only known samples of the virus are kept in secure laboratories in the United States and Russia for research purposes.