The forgotten ‘Vaccine Expedition’: a deed without parallel

The corvette María Pita, commissioned for the expedition, departing from the port of La Coruña in 1803 (engraving by Francisco Pérez). / Wikimedia

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Xavier Massó

Exactly 223 years ago, on 30 November 1803, the corvette María Pita slipped out of the harbour at La Coruña, marking the beginning of the Real Expedición Filantrópica de la Vacuna (Royal Philanthropic Vaccine Expedition)—an extraordinary venture whose purpose was to carry the smallpox vaccine to the furthest outposts of the Spanish Empire. Edward Jenner, the English physician who had discovered the very principle of vaccination, declared: “I do not imagine that the annals of history contain an example of philanthropy so noble and so extensive as this”. The enterprise is also known as the Balmis Expedition, after the surgeon and military doctor who led it, the Valencian Francisco Xavier Balmis y Berenguer (1753–1819).

Smallpox was one of the era’s most feared scourges. In 1796, the country doctor Edward Jenner had demonstrated that cowpox—a far milder cousin of the lethal human disease—could confer protection. He took lymph from infected cows and inoculated a young boy, who duly acquired immunity. The principle of vaccination had been established. Jenner published his findings in 1798; by 1800 they had already reached Spain, specifically Puigcerdà, where Dr Francisco Piguillem secured lymph on his own initiative and began to administer it with marked success.

Balmis, whose medical career was distinguished and wide-ranging, had been appointed honorary physician at the court of Charles IV. On hearing of Piguillem’s work, he persuaded the king of the need for a formal expedition. Charles IV—acutely sensitive to the issue, having lost a daughter to smallpox—agreed to sponsor and fund the ambitious scheme.

Balmis’s second-in-command was another eminent military doctor and surgeon, the Catalan José Salvany y Lleopart (1778–1810). The chief nurse was Isabel Zendal (1773–????), director of the La Coruña orphanage. They were accompanied by two assistant physicians, two medical orderlies and three nurses. The aim was not merely to vaccinate local populations, but also to establish vaccination boards in the cities they visited, ensuring both the conservation of the lymph and the immunisation of future generations.

The expedition’s greatest challenge was preserving the vaccine during the long Atlantic crossing. Balmis’s solution was ingenious: a living chain of 22 unvaccinated orphan boys—one of them Zendal’s own son. Before departure, two boys were vaccinated and kept apart from the others. Once the pathological process had run its course—nine to twelve days—and they had gained immunity, lymph was taken from their pustules and used to inoculate another pair, and so on. Only one child died during the entire journey; the rest were left at various points along the route, taken in by local families.

The María Pita sailed with a crew of 37, in addition to the 22 boys. On board were surgical instruments, scientific apparatus and hundreds of copies of the ‘Tratado práctico e histórico de la vacuna’ (Practical and Historical Treatise on the Vaccine), to be distributed wherever they travelled. The expedition carried the vaccine to the Canary Islands, the Americas, the Philippines and China. The total number of those vaccinated is uncertain, but estimates suggest around one and a half million. In Cuba alone, roughly 400,000 people were inoculated.

In Puerto Rico, the team encountered an unexpected discovery: the Catalan doctor Francisco Oller Ferrer had already been practising preventive smallpox inoculation with lymph since 1792. In Venezuela, the expedition divided in two. Salvany ventured inland towards present-day Colombia, Peru and Bolivia, dying from the privations of the journey in Cochabamba on 21 July 1810—seven years after setting sail from La Coruña. Balmis, meanwhile, travelled through Venezuela, Cuba, Florida, Texas and Mexico. In 1805 he sailed from Acapulco to the Philippines. From there, he continued to China and, on his return, even vaccinated British residents on the island of St Helena. Learning there of Napoleon’s invasion of Spain, he headed for New Spain, arriving in 1810. He did not return to Spain until 1814, dying in Madrid on 12 February 1819. Isabel Zendal, for her part, remained in Puebla (Mexico) with her son after returning from the Philippines and never came back to Spain.

The expedition was a pioneering endeavour in preventive and humanitarian medicine—an ambitious and admirable accomplishment, sadly consigned to near-oblivion today. Of the Balmis Expedition, Alexander von Humboldt observed: “This voyage will remain the most memorable in the annals of history”.

Source: educational EVIDENCE

Rights: Creative Commons