[Andrés Bello and the royal philanthropic vaccine expedition].

In 1803 [corrected], Charles IV King of Spain, sent an expedition to perform widespread ("arm to arm") vaccination against smallpox in the American colonies. The expedition led by Dr Francisco Javier de Belmis visited Puerto Rico, Venezuela, Central America, Colombia, Ecuador, Perú, Bolivia and Chile. A poem to the vaccine was written by Andres Bello, the first rector of the University of Chile, then in Venezuela (1804). The expedition reached Chile in 1807, led by Dr Julián Grajales. This expedition was the most important medical act in the history of the Spanish colonies.