How was nasal insufflation used for smallpox variolation in China?

In China, nasal insufflation was a historical method of variolation used to immunize healthy individuals against smallpox. Dating back to the 16th century, the procedure involved physicians grinding dried smallpox scabs into a powder. This material was then blown through a pipe directly into the patient’s nose.1

By introducing this substance into the nasal passage, practitioners aimed to induce a milder, less dangerous form of the disease compared to a natural infection. While this practice helped reduce mortality, it remained risky because recipients could still develop full-blown smallpox and potentially transmit the virus to others. Consequently, variolation was eventually superseded by safer vaccination methods, such as those developed by Edward Jenner using cowpox.12