Arm to Arm

The Tower of Hercules was slipping further and further behind, smaller and smaller, as the corvette María Pita headed out into the Atlantic. It was 30 November 1803, and Isabel Zendal, sitting on deck, had her arms around the two youngest children to shield them from the wind.

Isabel was the director of the foundling home in A Coruña. On board were twenty-two orphans aged between three and nine; one of them was her own son, Benito. None of them had had smallpox, a disease that killed thousands of people every year on both sides of the ocean.

A few years earlier, the English doctor Edward Jenner had discovered that anyone who caught cowpox, which was far milder, was protected against the human disease. That’s where the word “vaccine” came from, from the Latin for cow. The doctor Francisco Javier Balmis, head of the expedition, wanted to take that remedy to Spain’s territories in the Americas. The problem was the journey: outside the body, the vaccine fluid went off within a few days, and the crossing would take weeks.

Balmis’s solution was as simple as it was risky. Before setting sail, they vaccinated two children. After nine or ten days, small blisters would appear on their arms; fluid would be taken from them to vaccinate another two, and so on, from arm to arm, all the way to the Americas. Always two at a time: if it didn’t take in one, there was still the other.

Isabel’s job was to make sure nothing broke that chain. She watched for fevers, changed bandages and kept the vaccinated children apart from the others, so that nobody would catch it before their turn.

In the hold there were also boxes of books: printed handbooks to teach the doctors in the Americas to vaccinate by themselves. The first stop would be the Canary Islands. Isabel looked at the little boy asleep with his arm bandaged and counted the days left until the next pair.