May 21, 2022

Vaccination is a vaccination against smallpox. The vaccine is attached to a Y-shaped device (two-pronged needle), pierced into the upper arm of a person, scratched, and inoculated intradermally. Since the smallpox virus was eradicated in 1980 and is considered to be non-existent in nature, it has not been carried out in Japan since 1976.


Since ancient times, in West Asia and China, the variolation method has been practiced in which healthy people are inoculated with pus from smallpox patients to cause mild smallpox and obtain immunity. Various variolation methods are described in "Isou Kinkan" (1742) published during the Qianlong Emperor era in the Qing dynasty of China. It led to (described later). However, in some cases, it became severe by several percent, and the safety was not sufficient. In 1796, English doctor Edward Jenner noted the hearsay that cowpox does not result in smallpox in homes and areas where cattle are raised. He devised a safe cowpox method using this pus, which spread all over the world and was effective in controlling the epidemic of smallpox. The word vaccine was also used at this time. It is called "Vaccinia virus" and is derived from the Latin word Vacca (vaccine cow), which is the origin of vaccine (vaccine) and vaccination (vaccination). However, later studies revealed that cowpox virus and smallpox virus had no immune crossing effect. It was actually due to another virus in cowpox pus, so it was a coincidence that Jenner was able to produce a smallpox vaccine. The origin was unknown for many years. However, DNA analysis of a 1902 smallpox vaccine sample showed that it was 99.7% similar to horsepox virus, indicating that it was horsepox virus or a closely related species. .. Derrick Baxby, a leader in vaccinia virus research, supports the origin of the horsepox virus and is infected with the horsepox virus, causing inflammation and fat "horse grease" on the heel of the horse. Was the origin. He actually inoculated smallpox and proved that he was immune to infected people who came into contact with horse grease. However, it is still unclear whether the horsepox virus has a horse as its natural host or has been infected by other animals.

Introduced and spread to Japan

In Japan, in 1789, in the latter half of the Edo period, Ogata Shunsaku, a doctor of the Akizuki clan, inoculated the children of Oshoya and Amano Jinzaemon with the smallpox method and succeeded. This was not a method using cowpox devised by Jenner, but Ogata himself improved the method of powdering smallpox scabs and blowing them into the nostrils. In 1810, Goroji Nakagawa, who was abducted by Russia, introduced the vaccination method using cowpox after returning to Japan. In 1824, Japan's first vaccination technique was applied to Iku, the daughter of Masaemon Tanaka. Around this time, there were three outbreaks of smallpox in Ezo (now Hokkaido), and it is believed that he had vaccinated at this time. However, Goroji used the vaccination method as a secret technique and hardly told it, so few people knew it. The vaccination book he obtained was translated into Japanese in 1820 by Sajuro Baba, a translator of the Edo Shogunate. After that, the technique of vaccination was transmitted to Akita and then to Kyoto by doctors in Hakodate (currently Hakodate City, Hokkaido), Keizo Takagi, and Yuzo Shiratori. Apart from this, the same in 1813.