Variolation: The Prevention
It was commonly believed that the survivors of a smallpox attack were immune thereafter and would not catch the disease again. Thus, the preventive measures were attempted by introducing samples from smallpox vesicles into the scratched skin or nostrils of healthy subjects. It was hoped that this imitation of nature could induce some degree of immunity in other people. This process called variolation or inoculation, was practiced in China during 10th century and before that in India around 1000 BC.
The variolation was introduced in England by Lady Mary Wortley Montague (1689-1762); who was smallpox victim herself, by demonstrating its effectiveness in her own children. Though, variolation was later successfully experimented on prisoners as well, yet the ingenious preventive method was risky as the inoculated people suffered a rather virulent attack of the disease.