From the Cow to the Vaccine

200,000 years ago, the Homo neanderthalensis, the Neanderthal, occupied the hostile and cold lands in Europe, seeking for food and easily dying, very frequently, because of traumas, as a result of falls, accidents, and skirmishes while hunting or walking through long inhospitable trails; other times, they died simply due to starvation. It was very weird that individuals passed the 50-year-old mark and, as a consequence, there's no evidence that they suffered from degenerative illnesses. In the Neolithic, things changed; around 8,000 b.C., the climate became more benign and the necessity to move from one place to another to survive was vanishing, so the Homo viator finally settled, starting an appearing process of the first civilizations, intrinsic to the domestication of the beasts and plants.

Louis Pasteur in his Laboratory - 1885

However, in the contact with the primitive bovids, a bacterium with the name of Mycobacterium archaicum suffered a mutation into the modern bacterium that causes the infamous tuberculosis, Mycobacterium tuberculosis; according to different researchers, the oldest human illness. The tuberculosis story could be taken as a perfect metaphor of the fate of the human being, of their contingency against the whips of different malaises, terrible epidemics, of the illness in all its impenetrable vastness. God, not in vain, said to the man when he expelled him from heaven that "because you have listened to the voice of your wife and have eaten of the tree of which I commanded you, 'You shall not eat of it, cursed is the ground because of you; pain you shall eat of it all the days of your life; It will produce thorns and thistles for you, and you will eat the plants of the field. By the sweat of your brow, you will eat your food until you return to the ground since from it you were taken; for dust you are and to dust you will return."

The malaria in the Nile river around 2,000 b.C.; the pest in Athens in 430 b.C.; the so-called "plague of Justinian" in the 6th century; the leprosy; the Black Death in 1348; the second European plague pandemic in the 16th and 17th centuries; the smallpox and syphilis pests introduced by the Europeans in the New World; flus, cholera, measles, diphtheria, disasters in the harvests... From a long time ago, humans have lived together with the notion of epidemic (Greek term), a malignant and invisible agent that originates the illness, with the idea of effluvium, emanation, miasma, of an unhealthy and morbid atmosphere. The Hippocratic text Airs, waters and places already claimed that the diet, the climate and the earth quality, the winds and the water were factors that intervene in the development of population illnesses, because of their influence in the balanced relationship between the human being and their environment. So, although the effective discovery of living creatures, unnoticeable to the naked eye wasn't made till the end of the 17th century with the help of the microscope, their activities have been known by humanity since its own appearance (200,000 years ago), both their beneficial activities, for example, in the fermentation of alcoholic beverages, bread and cheese, and their harmful activities, in the form of infectious diseases. After the collapse of the classical civilization, medieval Western Europe returned to the religious-magical notions, and the belief of the contagion as illness source was substituted by a vision where health and death were synonyms of the divine punishment and forgiveness. It is important to highlight the Church hegemony in the science field.

The pioneer of the invention that would change the history of the fear towards the invisible and, indeed the history of illnesses; the antecedent of the investigations by a man who pasteurized the world, lived in England in the 18th century, a time where the smallpox virus was causing authentic scourges in Europe and America. Edward Jenner (1749-1823), a rural physician who settled in Berkeley after several years studying and practicing with the famous surgeon of the time John Hunter, in London, observed a few interesting things among the farmers of the area. It is said that in one occasion, Jenner heard a woman saying: "I cannot get smallpox because I am already vaccinated" and, it seems, he must have been having that phrase inside his head while on Berkeley, he saw the milkers had a "more benign" form of smallpox which didn't cause those terrible marks on the patients' faces. So, he came up with the conclusion that the milkers had the "cow smallpox" or "cowpox", much less virulent than human smallpox and, also the cowpox protected them against the latter one. Jenner started working on this issue very hard. At this point, I shall remind you that in 1721, lady Mary Wortley Montagu, an aristocrat who had suffered herself the illness, had already introduced in England the "vaccination" technique that she had seen from the Turkish during her stay in the city of Constantinople. The transmission of pustules from smallpox-sick people had been practicing in the ancient civilization in India, later translating this knowledge to the Chinese and later to the rest of Asia. In 1788 Jenner sent his discoveries to the medical board in London about his idea of a vaccine against smallpox, but his research didn't cause any enthusiasm among them. Between that year and 1796, he continued with his experimental studies until the momentous day on May 14. That day, Edward Jenner carried out the first vaccine inoculation against smallpox, in a healthy 8-year-old boy called James Phipps, using a secretion collected from a pustule in a milker's hand, called Sarah Nelmes, who had been infected while milking her cow Blossom. The young boy only developed a pustule in the inoculation area, which cleared out in a few days. 3 weeks later, once again, he inoculated him a tiny quantity of pus that came from a person suffering from the "more virulent" form of smallpox, or as he called it, human smallpox. The boy didn't get infected and this way it was demonstrated the prophylactic action of the inoculation against smallpox, using a small amount of cowpox. This explains why the virus used by Jenner, coming from a cow, was called "vaccine", from the Latin word "vacca-ae" which means "cow".

But it was finally Louis Pasteur, the great chemist who was famously awarded in the 19th century, who improved the technique and, in the memory of Edward Jenner, baptized it as "vaccine". However, the consolidation of microbiology (science that studies microorganisms) and of Pasteur's works, was closely related to a series of secular controversies that came from philosophy and religion with implications in the way of analyzing, observing and explaining the results. The most fascinating one was the "spontaneous generation controversy", or "abiogenesis", in other words, the formation of life from inert matter, also known as "autogenesis" or "spontaneous generation", is an ancient biology theory that supported the idea that animal and vegetable life could emerge from dead matter. This theory had been accepted by different philosophers, such as Aristotle himself, till the 17th century, when people started to refuse this primitive notion. Could living creatures emerge from the inert, in other words, from the intervention or mediation exclusively of chemical processes? Or, on the contrary, life always comes from life? These questions, are seen absurd nowadays, but at that time were two disputable questions, which confronted the Darwinians and the Creationists.

In a report to the "Académie des Sciences de Paris", 1860, "Expériences rélatives aux générations dites spontanées" (Experiences related to spontaneous generations), Pasteur communicated his simple and elegant experiments, which consisted in heating up infusions in glass flasks, where the content was in direct contact with the air. He proved that the germs from the air were retained through their path along the twisty flask necks, in the walls of the container, and they didn't reach the interior of it where the infusion was located, therefore the liquid stayed sterile indefinitely. Only if the neck of the container was broken, or if the container was tilted, the germs could infect the infusion and start a rapid growth. Thanks to this process, it was revealed that the liquid didn't develop microorganisms, so according to Pasteur, the idea that a chemical process was the cause of the occurrence of the germs had to be discarded.

Despite this, the eminent German chemist Justus von Liebig or his compatriot and close friend Felix Archimede Pouchet insisted that the fermentation process was purely chemical and that it didn't need the presence of any microorganism, that is, they believed it was an inorganic process. In 1864, putting the emperor Napoleon III aside, Pasteur investigated the cause of why the wine and beer became bitter as time passed, resulting in huge losses for the French wineries of the time. To try to find out the cause of this, Pasteur moved to Arbois, a place with a long wine tradition, where he spent much of his childhood. With the help of a microscope, he discovered that actually, two types of microorganisms intervened in the process, specifically, two types of yeast, which were the key to the fermentation process. One of them, called Saccharomyces cerevisiae, commonly known as "bread yeast" was the one that produced the alcohol and, the other one, called acetobacter, which is really a family of different specimens, produced the vinegar, and thus embittering the wine. Pasteur used a new method to eliminate the microorganisms that could spoil the wine or beer: it was about storing the liquid in very well-sealed tanks and then heating the liquid up to 111 ºF (44 ºC) during a short time. He discovered experimentally that the populations of acetobacter were reduced significantly, leaving the beverages "almost sterilized".

Taking advantage of the analogy that existed between the fermentation processes and the theory of germs applied to infectious illnesses, he published his "Germ theory of disease", according to which every infectious illness is caused by a germ with the ability to propagate among people, and he managed to find the vaccine against cholera (1884), erysipelas (1882) and rabies (1885).

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