Koyama Shisei (小山肆成)

Shisei KOYAMA (1807 - October 28, 1862) was a doctor who lived in the late Edo period. He developed the first domestic smallpox vaccine. His second name was Hoshu. His nickname was Keisuke.
In the field of medical science in Wakayama Prefecture, he and Seishu HANAOKA are both highly recognized and there is a common phrase 'Seishu of the north, and Hoshu of the south.'


He was born in 1807 to a jizamurai (high-ranking individual in a rural community) family in Hisagi Village, Muro County, Wakayama Prefecture (currently Hisagi, Shirahama Town, Nishi-Muro County, Wakayama Prefecture). His childhood name was Kobunji. He went to Kyoto when he was still young and studied diligently under his older brother Fumiaki KOYAMA. He started to pursue a medical career after his brother died in 1823. He studied Confucianism under Nangai OKADA, and studied medicine under Kien TAKAGAI, who was a doctor working at the Imperial Court. Shisei became an Imperial Court doctor and then opened his own clinic on Karasuma-dori Street.

Witnessing the outbreak of smallpox in the Kumano Region from 1838 to 1842, Shisei sold his family heirlooms such as swords to purchase cows to be used in his experiments. Then, using his own wife as an experimental subject, Shisei immersed himself in development of smallpox vaccine. In 1847, he translated the book on the principle of smallpox vaccination called "Intoryaku" and wrote "Into Shinpo Zensho" (The Principle of New Smallpox Vaccination).

He made a noteworthy contribution to medicine by inoculating with cowpox virus. In 1849, he developed gyukajintobyo, which was a high-immunity smallpox vaccine. Although his vaccine development was half a century later than a British doctor Edward JENNER, Shisei's vaccine allowed lower incidence and therefore has been highly recognized globally.

[Original Japanese]