This story was originally published in our September/October 2022 issue as "The First Global Vaccination Campaign." Click here to subscribe to read more stories like this one.
On Nov. 30, 1803, military physician Francisco Xavier de Balmis set off from the port of La Coruña in northwest Spain on what would become a three-year mission. On board with him were 22 orphan boys. Their goal: to complete the first global immunization campaign.
The world was riddled with smallpox, which killed one-third of all infected. Though Edward Jenner had discovered in 1797 that pus from a cow’s cowpox blisters could be used as a vaccine, the majority of the world had no access to the inoculation. Cowpox was such a local disease, mostly found in England and occasionally France or Italy, that it was unclear how anyone could scale vaccination to more people.
Scientists had yet to discover germ theory, so no one knew what a virus was. They did know that they needed to spread cowpox in order to keep the vaccine alive, but prior methods, like putting active disease material (in other words, pus) from an infected person onto cloth or in a vial and rubbing that into the wound of a recipient, didn’t work over long distances. Taking a whole cow to disease hotspots was equally impractical. Today, such viral material is kept alive by refrigeration — technology and know-how scientists just didn’t have back then.