In The Principles and Practice of Medicine, William Osler1 wrote that the patient with smallpox "presents a terrible picture, unequalled in any other disease; one which fully justifies the horror and fright with which small-pox is associated in the public mind." This terrifying image is supported by the World Health Organization's estimate that 10% of all human deaths have been caused by smallpox.2 Accordingly, the eradication of this disease is hailed as one of the great victories of modern medicine.
Lee AJ, Norton SA. The Scars of Smallpox. Arch Dermatol. 2003;139(3):279-280. doi:10.1001/archderm.139.3.279