An expedition led by Francisco Javier de Balmis departed A Coruña, Spain, with the aim of vaccinating millions in South America and Asia against smallpox.

The Royal Philanthropic Vaccine Expedition, commonly referred to as the Balmis Expedition, was a Spanish healthcare mission that lasted from 1803 to 1806, led by Dr Francisco Javier de Balmis, which vaccinated millions of inhabitants of Spanish America and Asia against smallpox. The vaccine was transported through children: orphaned boys who sailed with the expedition.

Francisco Javier de Balmis was a Spanish physician best known for leading an 1803 expedition to Spanish America and the Philippines to vaccinate populations against smallpox. His expedition was the first international vaccination campaign in history and one of the most important events in the history of medicine. It inspired recent vaccination efforts such as that of Carlos Canseco, president of Rotary International, to start the worldwide program PolioPlus to eradicate polio.

A Coruña is a city and municipality in Galicia, Spain. It is Galicia's second largest city, behind Vigo. The city is the provincial capital of the province of A Coruña, having also served as political capital of the Kingdom of Galicia from the 16th to the 19th centuries, and as a regional administrative centre between 1833 and 1982.

Smallpox was an infectious disease caused by Variola virus, which belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) certified the global eradication of the disease in 1980, making smallpox the only human disease to have been eradicated to date.