Why did people who milked cows allow the invention of vaccination?

This Tuesday October 15 marks the opening of the flu vaccination campaign. But protecting against disease in this way might never have been possible if humans had never milked cows.

To understand, you have to go back to 1749 and go to England. Edward Jenner is a country doctor who studied in London under a surgeon whose philosophy was: “Don’t believe, try!”. During his career, then that‘he is faced with smallpox, an extremely contagious diseasehe decides to apply his mentor’s adage to the letter.

At that time, one in five people died from this disease. The only way to hope for a cure is to inoculate the patient with the virus, either “heal evil with evil”. But this practice is extremely risky.

An 8-year-old boy voluntarily exposed to smallpox

Edward Jenner then observes something that will change everything. He notices that some of these patients suffer from a much less serious form of smallpox. The latter manifests itself only by small pustules located on the hands.

What’s even stranger is what all these people have in common: they milk cows, which are also affected by smallpox but in a more benign form. The British doctor hypothesizes that by inoculating this bovine form of smallpox into a healthy person, they will not be able to contract its deadly version, like these farm people who seem immune.

He decided to take the risk and, in 1796, took a little pus from the hands of a milkmaid before inoculate an 8 year old boy. James falls ill instantly. If Edward Jenner is worried, the miracle happens a few days later: the child has nothing left. The doctor, convinced that he has an important discovery, decides to expose James to smallpox patients.

And absolutely nothing happens: the boy does not contract smallpox. Edward Jenner has therefore just invented vaccination, which takes its name from the Latin “vacca”, which means “cow”, since they are at the origin of this discovery.

Fifty years later, mortality due to smallpox is divided by ten. This process will then be extended to other diseases thanks to the work of Louis and Marie Pasteur, and will give rise to vaccines which continue, even today, to save lives throughout the world.

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