Smallpox outbreaks killed many over the course of Japan's premodern history, with numerous notable historical outbreaks and a number of very prominent figures such as Shogun Tokugawa Tsunayoshi (d. 1709) and Emperor Kômei (d. 1867) dying of the disease. Though one type of smallpox vaccine was developed in the Ming Empire in the 16th century and implemented in Japan, instances of the disease declined dramatically after a modern form of the vaccine, developed by Edward Jenner in England in the late 1790s, was introduced to Japan in 1849 and implemented widely in the early 1850s.
Other notable historical figures who may have died of smallpox include Fujiwara no Fusasaki, Fujiwara no Maro, Fujiwara no Muchimaro, and Fujiwara no Umakai (all four, d. 737); Hôjô Ujinao (d. 1591); and the Shunzhi Emperor (Qing Dynasty, d. 1661).
A particularly significant smallpox epidemic broke out in the late 730s, killing roughly one-third the population of the Japanese islands in a two-year period.
The smallpox vaccine developed by Edward Jenner in Gloucestershire, England, was in fact the first modern vaccine to be developed, in concert with the idea that exposure to a milder or different form of a pathogen can help the human body to develop immunity to a more serious form of a disease. In 1796, Jenner famously exposed a young boy to pus from a milkmaid infected with cowpox, and then later exposed him to scabs taken from a smallpox patient; the boy did not develop smallpox. From this beginning, a means was developed for effectively immunizing people in a widespread manner. Such methods were introduced into Japan in 1849 via the Dutch at Nagasaki, and were quickly implemented; Satô Taizen, head of the Juntendô medical school in Sakura han began employing this method that same year, Saga han court physician Narabayashi Sôken implemented widespread immunization in Saga in 1850, and the Ryûkyû Kingdom ordered immunizations to be performed across the various Ryûkyû Islands in 1851.
- Lloyd Eastman, Family, Fields, and Ancestors: Constancy and Change in China's Social and Economic History, 1550-1949, Oxford University Press (1988), 5-6.
- Delmer M. Brown, John Whitney Hall, et al (eds.), The Cambridge History of Japan, vol 1 (1988), 250-251.
- "Jenner," Britannica kokusai daihyakka jiten, Britannica Japan, 2014.
- Pamphlet available at Juntendô Memorial Buildings Museum.
- Ishin Shiryô Kôyô 維新史料綱要, vol 1 (1937), 213.
- Ishin hiryô Kôyô, vol. 1, 320.