To vaccinate its colonies against smallpox, Spain sent a ship carrying 22 orphaned boys — the live vaccine passed arm-to-arm through their bodies across the Atlantic.
In 1803, Spain launched the Royal Philanthropic Vaccine Expedition to deliver Edward Jenner's new smallpox vaccine to its colonies in the Americas, the Philippines, and beyond. The problem: the cowpox vaccine could not survive a months-long ocean voyage in any storage container available at the time.
The solution was as brilliant as it was disturbing: 22 orphaned boys aged 3 to 10 were recruited to serve as living vaccine carriers. The vaccine was kept alive by passing it arm-to-arm from boy to boy in a chain across the Atlantic, each new boy inoculated from the last.
Leading the expedition was Dr. Francisco Xavier de Balmis, a Spanish royal physician. Alongside him was Isabel Zendal Gómez, the orphanage director who cared for the boys throughout the voyage — she is recognized by the World Health Organization as the first nurse to participate in an international humanitarian mission.
The expedition traveled for three years, vaccinating hundreds of thousands of people across Venezuela, Colombia, Ecuador, Peru, Mexico, the Philippines, and China. Wherever the team went, they also trained local doctors in how to continue the vaccination program after they left.
Edward Jenner himself, who invented the vaccine, called the expedition 'a philanthropy so noble, so extensive as to be without parallel in the annals of history.' The orphans who made it possible were never named in the official records.