What is immunity?
　　　

疫＝epidemic

免れる＝escape
免疫＝imumunity　

To escape from epidemic is immunity.
　
　

A long time ago, there were serious epidemics. Plague and smallpox.
:The plague

The plague is bacteria and many are in the inside of the body of a black rat.
If the flea which stabbed the rat stings man, the plague will occur to man.
　
oriental rat flea（female）

The plague is the infectious disease which was the highest through human beings' history as for the case fatality rate, and about 1/3 of the entire population of Europe became extinct in 1347-1353. It is said that it arrived at Europe north of the Alps in 1348 through central Asia and Messina in 1348.

■country not designated for an plague infected area (they have reported the occurrence before)

■country designated for an plague infected area (they have reported the patients before)

 

The plague in Japan

The epidemic in Japan begun at 32 Meiji era when a rat with a plague bacillus and the sailor infected with the plague landed at the Kobe harbor from Taiwan. The plague was expanded even to the surrounding area by this rat, and Ministry of Health and Welfare statistics says plague patient load was 2,912 persons and the death toll was 1,464 persons by 4 Showa era. .
　
 Discovery of a plague bacillus

A plague bacillus was discovered by Alexander Yersin at Hong Kong in 1894. Around the same time, Shibasaburou Kitazato who was a Japanese bacteriologist completely discovered independently.
　The left microscope was the one Kitazato used.
　

What is visible in the round is the plague bacillus seen under the microscope.
　

Smallpox
　

A smallpox virus goes into the most large-sized category in various viruses at about 200 millimicrons in diameter. Only humans are infected and fallen sick with the disease.
The revelation place of the smallpox is not clear. Probably what was the illness of other animals acquired the susceptibility and singularity to humans by a certain cause at first.
　It is said that the oldest example currently affirmed as having died of smallpox is the Ramses 5 generation of Dynasties of Ancient Egypt who died in B.C. of the 1100s
　
After the Columbus arrival, smallpox also invaded America and brought Native American serious damage.

It is said that Native Americans were not resistant to smallpox at all since they were unrelated to it, and the mortality rate was 90 percent depending on the place, some tribes were the wiped-out.

　
Smallpox in Japan
　The propagation to Japan is about the middle of the 6th century, and it is considered to be the first record of smallpox in the Nihon shoki (there is also a measles theory). One of the causes of the Great Buddha construction of Nara is this smallpox epidemic.
1885〜87 The 1st outbreak of smallpox 32,000 dead persons
1892〜94 The 2 st outbreak of smallpox 24,000 dead persons
1896〜97 The 3st outbreak of smallpox 16,000 dead persons
　
The person who eradicated smallpox is Edward Jenner
　The method of inoculating into a healthy human being the liquid extracted from the smallpox patient's pus-filled blister at the beginning of the 18th century was brought from the Arab world.
　

However, this prevention method was accompanied by danger.
　
Then, Jenner thought.
　A cow also has the illness similar to smallpox, and the milking persons who suffered from this cow disease knew that they were hard to contract smallpox. Then, Jenner thought that when planting the pus of the person of this milking in the ordinary person, that person did not contract smallpox.
The cowpox is an infectious disease caused by the cowpox viral infection
　
　When Jenner performed smallpox vaccination by cowpox, initially incomprehensive people had laughed scornfully at him with such comics.
　
　in１７９８
As Jenner thought, the people into whom the pus of the cow was inoculated escaped smallpox.
　
Eradication of smallpox
　The "world smallpox eradication program" was decided by WHO Assembly in 1958, and the eradication program started.

　In India where the damage of smallpox is especially the severest, since they had a religious idea  that happiness is brought to people suffered from smallpox, it seemed that the eradication was difficult.

When the smallpox patient was reported, WHO performed smallpox vaccination for people who contacted the patient from the one month before the onset of a disease, and took the plan which prevents infection spread of smallpox by preventing propagation and diffusion of a virus, and isolating them. This went well and the smallpox patients decreased dramatically in India.

This plan was used also in other areas.

　In 1977, the patient of the youth of Somalia was finally reported to the natural disease person, and WHO made the eradication declaration on May 8, 1980 which passed three years.
　

A smallpox virus is strictly managed with level 4 institution in the United States and Russia, and it is the non-disclosure now.


The smallpox is recognized that the virus itself does not exist in the natural world now, and is the only thing as infection which human beings eradicated.


In Japan, the patient was finally reported in 1955, and the smallpox was eradicated.

The vaccination was abolished by eradication movement by WHO from 1976 onward.

　免疫療法をワクチンというわけは？：The reason to call a therapy of immunity vaccine is...

ジェンナーはめすうしで種痘を作った。：Jenner make variolation by cow

雌牛：cow