Smallpox was an ancient and much feared disease. It has been described as ‘one of the greatest scourges of mankind’. The disease is highly infectious, causes a painful illness and has a high mortality rate. It is also non-discriminatory, killing kings and queens as well as the poor. The most distinctive feature of smallpox is the spots, blisters and pustules which first appear on the face and limbs and then cover the whole body. Smallpox derives its name from these spots (pox), with the adjective small being used to distinguish it from the great pox (syphilis) [1–3].