The rapid diffusion of the jennerian method was founded in simplicity to practice, in its apparent effectiveness in combating smallpox and its epidemiological opportunity, as it appeared at the time of greatest recrudescence of the disease. The initial impulse for it's propagation, which originated a recognized movement to protect population health, was not without controversy. At the same time that defenders of the vaccine were added, opposite opinions appeared that used diverse critics to discredit it. The most common was to reveal their alleged failures using the media of the time, so cases were reported that occurred in the children of notable people in society. Ignacio María Ruiz de Luzuriaga (1763-1822), as secretary of the Royal Academy of Medicine he assumed a catalytic role, becoming the protagonist of the initial history of vaccination in Spain. It has been considered as an introducer, disseminator and ardent defender of the vaccine, as can be seen from the analysis of the bulky correspondence generated between 1801 and 1802 cataloged as "Papeles sobre la vacuna". These documents, preserved in the Academy library, show their activity as a propagator of the method and its capacity to respond to the doubts and concerns related to their possible adverse effects, avoiding jeopardizing the continuity of vaccines.