In the 1870s, he applied this immunization method to anthrax, which affected cattle, and aroused interest in combating other diseases.
Pasteur cultivated bacteria from the blood of animals infected with anthrax.
When he inoculated animals with the bacteria, anthrax occurred, proving that the bacteria was the cause of the disease.
Many cattle were dying of anthrax in "cursed fields".
Pasteur was told that sheep that died from anthrax were buried in the field.
Pasteur thought that earthworms might have brought the bacteria to the surface.
He found anthrax bacteria in earthworms' excrement, showing that he was correct.
He told the farmers not to bury dead animals in the fields.

In 1880, Pasteur's rival Jean-Joseph-Henri Toussaint, a veterinary surgeon, used carbolic acid to kill anthrax bacilli and tested the vaccine on sheep.
Pasteur thought that this type of killed vaccine should not work because he believed that attenuated bacteria used up nutrients that the bacteria needed to grow.
He thought oxidizing bacteria made them less virulent.
In early 1881, Pasteur discovered that growing anthrax bacilli at about 42 °C made them unable to produce spores, and he described this method in a speech to the French Academy of Sciences on February 28.
Later in 1881, veterinarian Hippolyte Rossignol proposed that the Société d'agriculture de Melun organize an experiment to test Pasteur's vaccine.
Pasteur agreed, and the experiment, conducted at Pouilly-le-Fort on sheep, goats and cows, was successful.
Pasteur did not directly disclose how he prepared the vaccines used at Pouilly-le-Fort.
His laboratory notebooks, now in the Bibliothèque Nationale in Paris, show that he actually used heat and potassium dichromate, similar to Toussaint's method.

The notion of a weak form of a disease causing immunity to the virulent version was not new; this had been known for a long time for smallpox.
Inoculation with smallpox (variolation) was known to result in a much less severe disease, and greatly reduced mortality, in comparison with the naturally acquired disease.
Edward Jenner had also studied vaccination using cowpox (vaccinia) to give cross-immunity to smallpox in the late 1790s, and by the early 1800s vaccination had spread to most of Europe.

The difference between smallpox vaccination and anthrax or chicken cholera vaccination was that the latter two disease organisms had been artificially weakened, so a naturally weak form of the disease organism did not need to be found.
This discovery revolutionized work in infectious diseases, and Pasteur gave these artificially weakened diseases the generic name of "vaccines", in honour of Jenner's discovery.

In 1876, Robert Koch had shown that Bacillus anthracis caused anthrax.
In his papers published between 1878 and 1880, Pasteur only mentioned Koch's work in a footnote.
Koch met Pasteur at the Seventh International Medical Congress in 1881.
A few months later, Koch wrote that Pasteur had used impure cultures and made errors.
In 1882, Pasteur replied to Koch in a speech, to which Koch responded aggressively.
Koch stated that Pasteur tested his vaccine on unsuitable animals and that Pasteur's research was not properly scientific.
In 1882, Koch wrote "On the Anthrax Inoculation", in which he refuted several of Pasteur's conclusions about anthrax and criticized Pasteur for keeping his methods secret, jumping to conclusions, and being imprecise.
In 1883, Pasteur wrote that he used cultures prepared in a similar way to his successful fermentation experiments and that Koch misinterpreted statistics and ignored Pasteur's work on silkworms.
In the 1870s, he applied this immunization method to anthrax, which affected cattle, and aroused interest in combating other diseases. Pasteur cultivated bacteria from the blood of animals infected with anthrax. When he inoculated animals with the bacteria, anthrax occurred, proving that the bacteria was the cause of the disease. Many cattle were dying of anthrax in "cursed fields". Pasteur was told that sheep that died from anthrax were buried in the field. Pasteur thought that earthworms might have brought the bacteria to the surface. He found anthrax bacteria in earthworms' excrement, showing that he was correct. He told the farmers not to bury dead animals in the fields.
In 1880, Pasteur's rival Jean-Joseph-Henri Toussaint, a veterinary surgeon, used carbolic acid to kill anthrax bacilli and tested the vaccine on sheep. Pasteur thought that this type of killed vaccine should not work because he believed that attenuated bacteria used up nutrients that the bacteria needed to grow. He thought oxidizing bacteria made them less virulent. In early 1881, Pasteur discovered that growing anthrax bacilli at about 42 °C made them unable to produce spores, and he described this method in a speech to the French Academy of Sciences on February 28. Later in 1881, veterinarian Hippolyte Rossignol proposed that the Société d'agriculture de Melun organize an experiment to test Pasteur's vaccine. Pasteur agreed, and the experiment, conducted at Pouilly-le-Fort on sheep, goats and cows, was successful. Pasteur did not directly disclose how he prepared the vaccines used at Pouilly-le-Fort. His laboratory notebooks, now in the Bibliothèque Nationale in Paris, show that he actually used heat and potassium dichromate, similar to Toussaint's method.
The notion of a weak form of a disease causing immunity to the virulent version was not new; this had been known for a long time for smallpox. Inoculation with smallpox (variolation) was known to result in a much less severe disease, and greatly reduced mortality, in comparison with the naturally acquired disease. Edward Jenner had also studied vaccination using cowpox (vaccinia) to give cross-immunity to smallpox in the late 1790s, and by the early 1800s vaccination had spread to most of Europe.
The difference between smallpox vaccination and anthrax or chicken cholera vaccination was that the latter two disease organisms had been artificially weakened, so a naturally weak form of the disease organism did not need to be found. This discovery revolutionized work in infectious diseases, and Pasteur gave these artificially weakened diseases the generic name of "vaccines", in honour of Jenner's discovery.
In 1876, Robert Koch had shown that Bacillus anthracis caused anthrax. In his papers published between 1878 and 1880, Pasteur only mentioned Koch's work in a footnote. Koch met Pasteur at the Seventh International Medical Congress in 1881. A few months later, Koch wrote that Pasteur had used impure cultures and made errors. In 1882, Pasteur replied to Koch in a speech, to which Koch responded aggressively. Koch stated that Pasteur tested his vaccine on unsuitable animals and that Pasteur's research was not properly scientific. In 1882, Koch wrote "On the Anthrax Inoculation", in which he refuted several of Pasteur's conclusions about anthrax and criticized Pasteur for keeping his methods secret, jumping to conclusions, and being imprecise. In 1883, Pasteur wrote that he used cultures prepared in a similar way to his successful fermentation experiments and that Koch misinterpreted statistics and ignored Pasteur's work on silkworms.
Louis Pasteur