 One practice features Arab traders in Africa "buying-off" the disease in which a cloth that had been previously exposed to the sickness was to be tied to another child's arm to increase immunity.Another practice involved taking pus from a smallpox scab and putting it in the cut of a healthy individual in an attempt to have a mild case of the disease in the future rather than the effects becoming fatal.The trade of enslaved Africans in the Atlantic has its origins in the explorations of Portuguese mariners down the coast of West Africa in the 15th century.