The vaccine crossed the ocean in children's arms

In 1803 the smallpox vaccine already existed, but it had a huge logistical problem: it only survived a few days outside the human body, and America was more than a month away by sea. No fridges, no vials, nothing.

The Crown's solution was as brilliant as it was moving: the Royal Philanthropic Vaccine Expedition took aboard 22 orphan boys from A Coruña and vaccinated them two by two during the crossing. As pustules formed on one pair, the next pair was inoculated. The vaccine crossed the Atlantic alive, arm to arm.

Caring for the boys was Isabel Zendal, the orphanage's matron, regarded as history's first nurse on an international mission. The expedition went on to vaccinate hundreds of thousands of people across the Americas and the Philippines.

Jenner himself, the vaccine's inventor, wrote that he could imagine no example of philanthropy so noble and so vast. The highest possible praise: from the father of the invention.