variolation

The obsolete process of inoculating a susceptible person with material from a vesicle of a patient with smallpox. SYN: variolization.

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var·i·o·la·tion .var-ē-ə-'lā-shən n the deliberate inoculation of an uninfected person with the smallpox virus (as by contact with pustular matter) that was widely practiced before the era of vaccination as prophylaxis against the severe form of smallpox

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va·ri·o·la·tion (var″e-o-laґshən) deliberate inoculation with the virus of unmodified smallpox to produce immunity to the naturally occurring disease; this was done in China and elsewhere in the region from ancient times to the 20th century. Dried crusts of smallpox lesions were applied to the skin or nasal mucous membranes, or were ingested. A modified method used in Europe in the eighteenth century consisted of subcutaneous injection of material from the lesions. Variolation is now used only experimentally in animals.