Centuries after spreading smallpox, the Spanish led a global campaign to fight it
Colonizers brought Old World diseases to the Americas, devastating indigenous populations. Nearly 300 years later the Spanish king ordered an ambitious mission involving orphans, warships, and the first vaccine to fight one of the deadliest of all.

Smallpox likely originated in Egypt more than 3,000 years ago and spread across Asia, Africa, and later into western Europe. Invading Moors carried smallpox into Spain in a.d. 711. (Read about how devestating pandemics change us.)