Pasteur Institute

Although the center against rabies, directed by Jacques-Joseph Grancher and Émile Roux was more than functional, it became so overcrowded that it became necessary to build a structure that Pasteur had been calling with the name “Institute Pasteur” long before it was even built. Since Pasteur could not, for health reasons, do it himself, he delegated the task of the project and of creating the new building, situated on rue Dutot, to two of his most trusted colleagues, Grancher and Emile Duclaux.[2]^:65

From the beginning the Institute experienced some economical difficulties that it was able to overcome thanks to the help of the government, some foreign rulers and Madame Boucicaut, but this aid would not in any way restrain its independence, therefore respecting Pasteur's most important prerogative. The million francs left unused would not be sufficient to provide for the institute's needs for long, but the prestige and the social benefits it would bring to France justified and motivated the subsidy it would receive; also the money brought in from selling the vaccines in France and in the rest of the world would help in supporting it. In 1888 this foundation, which had obtained the full approval from the government, began to function, and from the beginning it was involved in the development and changes that France underwent during the last decades of the 19th century.[2]^:68

The statutes drawn by Pasteur and later approved by Duclaux and Grancher define, besides its absolute freedom and independence, the institute's internal structure: a rabies division controlled by Grancher, an anthrax one in Chamberland’s hands, who also supervised the department of microbiology, while Emile Roux dealt with microbial methods applied to medicine.

Men and woman working in classroom at the Institut Pasteur, ca. 1920

During the First World War the institute was not only involved in the prevention of sanitary risks but also had to deal with the demands of the moment. The most urgent matter was to vaccinate the troops against typhoid fever, easily contracted by the soldiers who often had no choice but to drink from small streams or puddles from the last rain. By September 1914, the institute was able to provide 670,000 doses of the needed vaccine and continued to produce it throughout the conflict. It is important to note that the war brought to light germs that during times of peace were concealed deep within the soil or in pockets of putrefaction and therefore it revealed the true nature and severity of some types of pathogens that would otherwise have remained unknown. That's how Michel Weinberg, Metchnikoff's scholar, disclosed the complex etiology of gas gangrene and created a vaccine for each one of the anaerobes associated with it.[2]^:147[3] The First World War involved science in warfare: a movement of active participation arose among researchers who felt the need to help France win the war. This is why Gabriel Bertrand, with Roux's authorization, crafted a grenade based on chloropicrin and Fourneau discovered the chemical reaction that led to the formation of methylarsine chloride, whose effects are even worse than the ones of other poisonous gases used during the war.

In 1938 the institute, despite its relative poverty, built a biochemical division and another one dedicated to cellular pathology, whose direction was entrusted to the hands of Boivin (who went on to discover endotoxins that are contained in the germ's body and are freed after its death). During the same period, Andre Lwoff assumed the direction of a new microbial physiology branch built on rue Dutot.[2]^:205 The general mobilization after France's declaration of war against Germany, in September 1939, emptied the Institute and significantly reduced its activities, as members of appropriate age and condition were recruited into the army, but the almost total absence of battles during the first months of the conflict helped maintain the sanitary situation on the front. After the occupation of France, the Germans never tried to gather information from the institute's research; their confidence in Germany's advantage in this field decreased their curiosity, and their only interest was in the serums and vaccines that it could provide to their troops or the European auxiliaries they recruited. This relative freedom allowed the institute to become, during the two years after the occupation, a great pharmacy for the Resistance thanks to the initiative of Vallery-Radot, Pasteur's nephew. The Germans became suspicious of the institute's staff only after an outbreak of typhoid in a Wehrmacht division that was stationed near Paris before being sent to the Russian front.[2]^:209–210 The cause of the epidemic was later found to be due to a member of the Institute stealing a culture of the germ responsible for the disease and, with the collaboration of an accomplice, infecting a large quantity of butter used to feed German troops. The fact that the epidemic spread after the Germans sold some of the butter to civilians was proof that the illness's breakout was not caused by local water quality. Afterwards, the German authorities ordered that the institute's stores containing microbial cultures could be opened only by authorized members; similar security problems also induced them to demand complete lists of the staff's names and functions; missing names caused the Germans to send two very valuable biologists, Dr. Wolmann and his wife, as well as other three lab assistants, to a concentration camp. The institute was not a location for German entrenchment even during the battles for Paris's liberation because of the honor and respect it commanded, as well as out of fear that involving it in any type of conflict might “free the ghosts of long defeated diseases”.[2]^:213

At the end of 1973 the institute's economic status was so worrisome that its troubles aroused the public's interest: no one could believe that an institution which was to provide vaccines and serums for more that fifty million people could be undergoing such big financial problems, an institution that furthermore was believed to be under government protection – like the Bank of France – and therefore shielded from bankruptcy. The causes of the decadence that brought the institute to financial ruins were numerous, but most of them were associated with its commercial and industrial activities and its management. Both the research and production branch had to endure the recoil caused by financial issues: the research branch didn't receive enough funds and the production branch, which was losing market ground to the new private labs, was immobilized by the antiquated mechanical equipment.

When in 1968, after disappearing for a long period, rabies reappeared in France, the institute, which owed its original celebrity to this disease's vaccine, was replaced by other pharmaceutical industries in the production of the vaccines; yet, despite the deficiencies in the organization's production branch, its members were able to produce, in 1968, over 400,000 doses of vaccine against the Hong Kong influenza.

In 1971 Jacques Monod announced a new era of modernization and development: this new awakening was symbolized by the construction of a new factory where all the production departments were to be reunited. Its construction cost forty-five million francs and the Government, impressed by the institute's will to change, granted it a sum of twenty million francs to bridge the deficit, followed by the people's initiative to also accept a role in the division of the financial responsibilities.[2]^:258

Production of antiserum at the Institut Pasteur in Paris

Not long after the institute's inauguration, Roux, now less occupied in the fight against rabies, resumed in a new lab and with the help of a new colleague, Yersin, his experiments on diphtheria. This disease used to kill thousands of children every year: an associated condition was commonly called croup, which created fake membranes in the small patients' throats, therefore killing them by suffocation. It was deservedly called “Horrible monster, sparrowhawk of the shadows” by Victor Hugo in his Art of being a grandfather. The painter Albert Gustaf Aristides Edelfelt made a famous painting portraying Pasteur in his laboratory while he was trying to cure this illness, which was fought at the times through procedures that were just as cruel as the illness itself.

Roux and Yersin grew the bacillus that causes it and studied, thanks to various experiments they did on rabbits, its pathogenic power and symptoms, like the paralysis of the respiratory muscles.[2]^:73 It is this last consequence of the diphtheria that provided the two researchers with a valuable clue of the nature of the disease, since it is caused by an intoxication due to a toxin introduced into the organism by the bacillus, that while secreting this particular venom is able to multiply itself: they were therefore inclined to think that the bacillus owed its virulence to the toxin. After filtrating the microbial culture of the Corynebacterium diphtheriae and injecting it into the lab animals, they were able to observe all the typical signs of the sickness. Roux and Yersin established that they were dealing with a new type of bacillus, not only able to proliferate and abundantly reproduce itself, but also capable of spreading at the same time a powerful venom, and they deduced that it can play the role of antigen, that is if they could overcome the delicate moment of its injection, made especially dangerous by the toxin.[2]^:74 Some German researchers had also discovered the diphtheria toxin and were trying to immunize some guinea pigs through the use of a vaccine: one of them, Von Behring, Robert Koch's student, stated that he was able to weaken small doses of the toxin. Nonetheless Roux was not convinced by this result, since no-one knew the collateral effects of the procedure, and preferred to use serotherapy since more than one lab study – like the one accomplished by Charles Richet – demonstrated that the serum of an animal vaccinated against the disease included the antibodies needed to defeat it. The anti-diphtheria serum which was able to agglutinate the bacteria and neutralize the toxin was supplied by a horse inoculated with the viral germs, and it was separated from the blood drawn from the horses’ jugular vein. Like it happened for his teacher with the anti-rabies vaccine, Roux needed to test the effectiveness of the product he elaborated, and endured all the stress and ethical dilemmas that the first use of such a risky but also groundbreaking procedure implied. To test the serum two groups of children were chosen from two different hospitals: in the first one, which received the serum, 338 out of 449 children survived, in the latter one, treated with the customary therapies, only 204 out of 520 survived. Once the results were made public by Le Figaro newspaper, a subscription fund was opened to raise the money needed to provide the Institute the number of horses necessary to produce enough serum to satisfy the national demand.[2]^:82

After Duclaux's death, Roux took his place as head of the institute, and the last research he carried out was the one on syphilis, a dangerous disease because of its immediate effects and the hereditary repercussions that result from it. Despite Fournier’s considerable work, van Swieten’s liquid mercury was still the only known cure, although its results were doubtful and uncertain. The search for a stronger remedy against this disease was made more difficult because most animals are immune to it: it was thus not possible to experiment possible cures and study their likely side effects.[2]^:128 The sexually transmittable Treponema pallidum (the syphilis germ), detected by two German biologists, Schaudinn and Hoffmann, affects only the human race – where it resides in sperm, ulceration and cancers that it is able to cause – and, as it will be later discovered, some anthropoid apes, especially chimpanzees. Both Roux and Metchnikoff, consequent to the discovery that this type of ape can be contaminated with the illness, contributed with their research in creating a vaccine, while Bordet and Wassermann elaborated a solution that was able to expose the germ’s presence in human blood. Even though it was not yet a completely reliable solution, it represented a noteworthy evolution compared to the previous medicines used against syphilis.[2]^:129

Ilya Ilyich Mechnikov already announced the “principle of immunization” during his voluntary exile in Italy, where he went to undertake some studies, the results of which he had promptly communicated to Pasteur. The phagocytosis theory is based on the notion that phagocytes are cells that have the power to englobe foreign bodies – and above all bacteria – introduced inside an organism. German biologists opposed to his doctrine the humoral theory: they claimed to have found in Roux's serum some substances able to reveal the presence of microbes, and to ensure their destruction if properly stimulated. The German scientist Eduard Buchner referred to these substances as “alexine” and two other biologists, Von Behring and Kitasato, demonstrated their lytic power towards bacteria.[2]^:83 In 1894 one of these scientist published the result of an experiment that appeared to completely refute Metchnikoff's ideas: using the cholera vibrio, discovered ten years before by Robert Koch, as an antigen, Richard F. J. Pfeiffer introduced it in the abdomen of a guinea pig already vaccinated against this disease, and was able to observe the destruction of the vibrio in the local blood plasma, without the participation of the phagocytes. Not even this study was able to shake Metchnikoff's belief and faith in his theory, and his ideas, as well as Pfeiffer's and Buchner's, would all contribute to the elaboration of the current theory of the immune system.

Yersin, after his research with Roux, abruptly left the Institute for personal reasons, without losing Pasteur's benevolence, who never doubted that the young man was destined to great things in the scientific area and would contribute in spreading Pasteur's discoveries around the world. The news of a violent plague outburst in Yunman enabled Yersin to truly show and reach his potential as he was summoned, as Pasteur's scholar, to conduct a microbiological research of the disease. The plague he had to deal with was the bubonic plague, which is recognizable most of the time through the abscesses, known as buboes, it provokes in its victims. Yersin looked for the germ responsible for the infection specifically in these plague-spots, tumors caused by the inflammation of the lymphatic glands which become black because of the necrosis of the tissue.[2]^:91 After many microscopic exams he was able to state that in most of the cases the bubonic plague bacterium was located in these buboes; but in the meanwhile the Japanese scientist Kitasato also declared that he had isolated the bacterium, even though the description he provided was dissimilar to the one given by Yersin. Therefore, although at first named “Kitasato-Yersin bacillus” by the scientific community, the microbe will later assume only the latter's name because the one identified by Kitasato, a type of streptococcus, cannot be found in the lymphatic glands. However it is Paul-Louis Simond who was the first to understand and describe the etiology of the plague and its modality of contamination: he observes all over the bodies of the people affected by it small flea-bites, which he also found on the bodies of the dead rats that were always linked to the plague, and then deduced that the fleas which carried the bacteria were its true vector or source, and that they transmitted the illness by jumping from the dead rats' bodies to the human ones and biting them.[2]^:94

Paul-Louis Simond injecting a plague vaccine on the 4th of June 1898 in the Vishandas Hospital, Karachi

By the beginning of the 20th century, the improvement of the general life conditions and the development of a more extensive conception of hygiene produced in France a slight regression in tuberculosis cases: nonetheless the institute's labs, like many other ones, kept trying to find among the Koch's bacillus many singularities the one that would allow them to find an antidote to its terrible consequences. Right after he had discovered the bacillus, Koch had tried in vain to create a vaccine against it, however the injection of the filtrate he had prepared, later called tuberculin, had the effect of revealing who was phthisic from who wasn't by causing in the latter—and not in the former—fever and light trembling.

The institute's newspaper was filled at the time with articles regarding tuberculosis, some of which written by Albert Calmette, who extended his research to a socio-professional category which was extremely affected by it, that is the miners in whom this disease is often anticipated or accompanied by silicosis and anchylostomiasis (caused by a small intestinal worm that creates a state of anemia propitious to tuberculosis).[2]^:140 After finding a better solution to anchylostomiasis, he focused on creating a vaccine using the bacillus responsible for bovine tuberculosis, very similar to the human one, as it caused almost the same symptoms. Having observed that most actinomycetales are saprophytes, that is able to survive outside of living organisms, with the help of a veterinary, Camille Guerin, he attempted to create a special nutritious environment for the bacillus that, in time, altered its features by eliminating the virulence and leaving only the antigenic power. Both of the scientist knew that this arduous task would require a lot of effort and time, because it was necessary to act on a large number of generations to change the genetic foundation of a species, nevertheless the velocity of the bacteria's reproduction allowed, since it was constantly monitored, to interfere with an important phase of its evolution. The environment deemed appropriate for the denaturation of the Mycobacterium bovis was a compost of potatoes cooked in the bile of an ox treated with glycerine, and Calmette re-inseminated it every three weeks for thirteen years, while checking for an enfeeblement of the pathogenic power of the bacillus. Having finally lost completely its virulence, the bovine tuberculosis germ grown with their method was the principal prophylactic weapon against human tuberculosis, and it helped to reduce considerably the frequency of this disease.

While experimenting on chimpanzees in Kindia, on which he was able to test exhaustively his vaccine, Calmette also discovered that it can notably weaken some leprosy manifestations – its bacillus presents some similarities with Koch's.[2]^:186

In Saigon Albert Calmette also created the first overseas branch of the institute, where he produced an amount of smallpox and rabies vaccines sufficient to satisfy the needs of the population, and started a study on venomous snakes, particularly cobras. During these studies Calmette discovered that the power of the venom, as well as that of tetanus, could be annihilated by the use of alkaline hypochlorites, and was able therefore to create a serum, effective if injected right after the cobra's bite. Back in France, he acquired enough snakes to continue his work and create serum for the local population.[2]^:98

The scientist and writer Charles Nicolle while in Tunis studied how epidemic typhus – known for the red spots it left on sick people that disappeared before their death – was transmitted. His insight into the mode of transmission occurred while he was visiting the hospital: patients were washed and given clean clothes on admission, and no new cases occurred within the hospital. This made him realise that the vector of the disease were lice that were discarded with the patient's own clothes.[4] Nicolle managed to attract Hélène Sparrow to be Laboratory Chief in Tunis. She had worked with Rudolf Weigl who had developed a vaccine, and she was able to introduce this to Tunisia as the start of a public health programme to control the disease.[5] Nevertheless, three other scientists identified the bacterium responsible for the disease: Ricketts, Russell Morse Wilder (1885–1959), and Prowazek, who called it Rickettsia prowazekii.[2]^:101

During the summer of 1900, the extremely hot weather and scarcity of the water supply in Paris, usually ensured by the Ourcq channel and by the de la Dhuis aqueduct, forced the authorities to pump water directly from the Seine, which, despite filtering, led to a sudden and alarming outbreak of typhoid cases in Paris. The cause of the disease, a bacillus that was discovered almost twenty years before by the German bacteriologist Karl Joseph Eberth and that looks like a bodyless spider, was constantly present in this river and not even pouring extensive quantities of ozone and of lime permanganate into its water was enough to exterminate the bacteria.[2]^:111 The difficulty in creating a vaccine is caused by the nature of the germ's endotoxins. Unlike diphtheria, which releases toxins via exocytotic secretion, typhoid pathogens encapsulate endotoxins which survive even after the death of the bacillus.

After working in the rabies division of Rue Vaquelin and studying the microbe that causes dysentery, André Chantemesse collaborated with a younger bacteriologist, Georges-Fernand Widal. Together they were able to immunize guinea pigs by inoculating them with heat-treated dead bacteria, calling into question the notion that only weakened, not dead, bacteria can be used to immunize.[2]^:112 They concluded that a series of three or four early injections of such heat-inactivated bacteria can effectively inoculate against development of the disease, as the endotoxins alone are sufficient to trigger the production of antibodies.

Regarding curative medicine, it was in 1911 that it took off at the Institut Pasteur, when Ernest Fourneau created the Laboratory of Medicinal Chemistry, which he directed until 1944, and from which emerged numerous drugs, among which one can mention the first pentavalent arsenical treatment (Stovarsol), the first synthetic alpha-adrenoreceptor antagonist (Prosympal), the first antihistamine (Piperoxan), the first active drug on heart rate (Dacorene) or the first synthetic no-depolarising muscle relaxant (Flaxedil). The discovery of the therapeutic properties of sulfanilamide by Tréfouël, Nitti and Bovet, in the laboratory of Fourneau, paved the way for the sulfamidotherapy.[6][7]

The work done in the new pavilion by Duclaux clarified how the human body accomplished some of its vital functions, and brought to light the role of a diastase. It was critical in resolving a controversy aroused between Pasteur and Berthelot after the publication of Claude Bernard’s posthumous essay regarding the nature of the agents implicated in some transformations that happen inside plants, like fermentation. While Pasteur believed that the only substance implied in the process of fermentation was yeast, Bernard – and Berthelot in his own way – believed that some other soluble ferment was involved: the German chemist Eduard Buchner later demonstrated the existence of this “ferment”, an intracellular diastase which he called “zymase,” what we know now as enzymes. Duclaux's study on the metabolism of nutrients did not have immediate practical applications, but later revealed how extensive is the field of enzymes and opened new roads that would lead biology to extend the knowledge on life's mechanisms on a molecular level.[2]^:119