Pasteur Vaccinations

PASTEUR VACCINATIONS, or antirabic vaccinations, are a prophylactic measure against rabies (see). As an antigen, a fixed virus (virus fixe) (see Rabies) is used, which to this day continues to be passaged almost everywhere from the virus originally obtained by Pasteur in Paris; over 2,000 such passages have already been conducted in the USSR at some stations. Only the Kiev and Dnepropetrovsk Pasteur stations worked for a time with a vaccine from a virus of local origin. In view of the fact that the causative agent of rabies in its pure form is unknown, it has to be studied in the tissues (brain) of the organism. This makes the task technically difficult and sometimes does not ensure the receipt of completely accurate and constant results. Nevertheless, many of the properties of virus fixe have been established. It is known that a number of physical and chemical agents act on it in a weakening manner; these include sunlight, X-rays, radium, high temperature, oxygen, bile, gastric juice, mercuric chloride, formalin, phenols, ether, and others. At low temperatures, virus fixe is preserved for a very long time; putrefaction acts on it weakly, and it is well preserved in glycerin. All these data have great practical significance, and many of the mentioned agents have been used to weaken the virus, to develop methods for its longer preservation, etc. The gray matter is the most virulent in the brain, with the infectious agent contained in greater quantity in the medulla oblongata, in the cerebral cortex, and in the Ammon's horn. The saliva of rabid animals is undoubtedly virulent, and practically, bites from dogs 10–12–15 days before the appearance of obvious signs of the disease should be considered dangerous; the question of whether the saliva of a person suffering from hydrophobia is virulent has not yet been resolved; the question regarding the virulence of the blood of animals sick with rabies and their milk also remains doubtful. The breed of animals through which it is passaged, the climate, conditions, etc., influence the virus fixe. Naturally, tens of years (since 1885) of passaging the virus in different places, in various climatic conditions, on different animals, with unequal technical methods, etc., must have influenced it, and indeed its biological properties at the present time differ significantly from those that were known under Pasteur. Such observations exist abroad (Fermi, Kraus, Remlinger, and others), and the Pasteur stations of the USSR also possess such data (Dubrovinsky). Compared to Pasteur's initial data, the virus has become more virulent for rabbits (shortening of the incubation period and the time of death after infection) and less virulent for humans, less resistant to external influences, etc. These circumstances have played a large role in antirabic vaccinations and the methodology of their application. Despite the indicated deviations, virus fixe still basically retains its constant features, by which it can be distinguished from the street virus. According to a number of authors (Gerlach, Kraus, Schweinburg), these differences boil down to the following (Table 1): Speed of reproduction in the central nervous system. Pasteur (see) built the method of antirabic vaccinations on the same principle by which he proposed prophylactic vaccinations in relation to other infectious diseases (chicken cholera, anthrax, etc.). Since the causative agent of rabies in its pure form is unknown, it is necessary to use the brain tissue of an infected animal, in which this virus is contained in a large quantity, for the manufacture of the vaccine. In this case, it is necessary to take an animal in which this virus develops with a certain strength but is distinguished by weak virulence for humans. Before Pasteur, there were only scattered data on this issue, namely, that the rabbit is susceptible to rabies and suitable for experimentation, that the brain contains the virus in a large quantity, that the saliva of an animal sick with rabies contains the rabies poison, and that it is possible to induce non-susceptibility in animals to this disease by introducing infected saliva. Through the works of Pasteur and his students (Roux, Chamberland, Thuillier), it was established that: 1) the rabies virus is localized in the central nervous system; through long passages through the rabbit organism, the virus acquires maximum toxicity for this animal, i.e., becomes a fixed poison; 2) when using the subdural method of rabies infection, the possibility of correct experimentation and study of the properties of virus fixe is ensured, and thereby possibilities are created for the use of this substance for the purposes of prophylactic treatment; 3) when drying the spinal cord infected with virus fixe over caustic potash, it systematically weakens and only after 13–15 days, when stored at a temperature of 20–24°, does it completely lose its virulence; 4) if, during vaccination with brains from rabbits sick with rabies, one begins vaccinations with a non-virulent vaccine and systematically strengthens them until the use of completely fresh brains, it is possible to impart non-susceptibility to rabies to both animals and humans; such vaccination is safe; 5) in view of the duration of the incubation period in rabies (usually not less than 20–30 days in humans), prophylactic treatment calculated for the duration of the incubation period is possible. The method proposed by Pasteur basically boils down to the following: the spinal cord, extracted from a rabbit that has died or been killed during agony, infected with virus fixe, is dried in a jar over caustic potash at a temperature of 20–24°. Pasteur's initial scheme provided for treatment in which the injection began with brains of 14-day drying; gradually reducing the duration of drying, Pasteur reached a vaccine of 3-day drying. Pasteur believed that drying leads to the weakening of virus fixe, but that another substance (matière vaccinale) is preserved in the brain tissue, which is capable of causing immunity during vaccination. Depending on the severity of the bites, Pasteur proposed a number of treatment schemes. In mild cases (traitement simple), the treatment lasted up to 15 days; in cases of moderate severity—up to 18 days; in severe cases (traitement intense)—up to 21 days. According to the latter scheme, brains of two-day drying are also introduced. In all cases, 2–3 cm³, and sometimes 1 cm³ of emulsion, were introduced (3 cm³ of emulsion contained 2 linear millimeters of spinal cord). Over time, it had to be stated that in a certain part of cases, the vaccinations did not have an effect. Under the influence of these failures, Pasteur himself began to systematically switch to a more intensive method of vaccination, using a more virulent vaccine by shortening the duration of brain drying. Pasteur believed that a rapid transition to less dried, i.e., still virulent, brains is dangerous for humans (rage atténuée), but in severe cases, he went for this out of fear that with such bites, a short incubation period is possible and, therefore, it is necessary to more quickly impart immunity against rabies to the organism. The intensification of the Pasteur method continued at the Paris Pasteur Institute even after Pasteur's death; starting from 1912, the following scheme is used here (3 cm³ of emulsion accounts for each vaccination) (Table 2). Pasteur stations in other countries went further in their changes to the Pasteur method in the direction of its intensification. Thus, in the Pasteur department of the Koch Institute for Infectious Diseases in Berlin, 2 cm³ of spinal cord emulsion was introduced daily for 21 days. The emulsion was prepared at the rate of 2 cm of spinal cord per 10 cm³ of physiological solution. In severe cases, the dosage was increased.

Treatment was extended to 4–6 weeks, and after a month had passed, repeat treatment was also performed. In view of the fact that cases of paralysis among those treated became more frequent with this method, the Koch Institute was forced in 1916–17 to switch to a weaker regimen, in which treatment began with brains dried for five days, and in cases of ordinary severity, they did not go below three-day drying. Russian Pasteur stations, where the original Pasteur method had been used since 1886, also gradually strengthened the initial regimens over time. The Moscow station, and following it a significant number of other stations, starting in 1923, excluded brains dried for four days. Until 1929, the Moscow station adhered to the following regimen (Table 3). (The emulsion was prepared from 1 mg of brain per 1 g of physiological saline without the addition of any preservative substances whatsoever.) In very severe cases in Moscow, two-day brains were sometimes replaced with one-day brains, but this was resorted to with great caution due to the fear of complications from vaccinations in the form of paralysis. In these cases, repeat treatment was also applied two weeks after the end of the first course of treatment (the first 15 vaccinations according to the basic regimen). In Leningrad, treatment with brains dried for three and two days has been used since 1920. In Odessa, until recent years, brains dried for four to one days have been used. In Samara, as early as 1914, treatment began with brains dried for five days and was brought down to one-day brains; a regimen was introduced in which treatment began with brains dried for three days and was brought to fresh brains. Here, therefore, they moved faster than in other places along the line of intensification. The objective necessity to intensify Pasteur vaccinations and the accumulation of facts regarding the harmlessness of fresh fixed virus for humans upon subcutaneous administration naturally led to the fact that stations are gradually switching from the Pasteur method to other methods. Some of these are built on the principle of using fresh fixed virus; others use phenol, ether, etc., instead of potassium hydroxide to attenuate the virus, with which it is easier to refine the dosage. These methods are, moreover, more economical and allow for more sterile work. Dilution methods. Hogyes's method. Hogyes began using his original method in Budapest in 1887. He justifies his method with the premise that the degree of attenuation of the brain during drying over potassium hydroxide depends on the remaining amount of live virus, that immunizing substances are inseparable from the fixed virus, and that it is possible, without danger to the organism of an animal or human, to begin vaccination by introducing fresh virus in small doses. Proceeding from the fact that by diluting the brain one can obtain such quantities of virus that correspond in content of rabies pathogens to brains dried over potassium hydroxide for specific periods, Hogyes developed his dilution method of prophylactic treatment for people. He began with vaccinations in a dilution of 1:10,000; systematically increasing the dose, he brought it to 1:100. With each vaccination, from 1 to 3 cm³ of emulsion was introduced. Depending on the severity of the bites, the amount of introduced virus was changed accordingly. In mild cases, the course of treatment lasted 14 days with two vaccinations daily—morning and evening—and in severe cases, the number of vaccinations was increased daily to 3–4, and treatment continued for up to 20 days. For the same reasons as the Pasteur method, the Hogyes method was subsequently strengthened accordingly. At the present time, in the Budapest Institute, vaccinations are used according to the regimen proposed by Szekely. He begins treatment with a dilution of 1:2,000, quickly increases the dosage, and brings the dilution to 1:100. He introduced 1-2-3-day pauses, therefore his treatment, which actually lasted only 13 days, ends only 21 days from the start of vaccinations. In addition, he provides for an additional course of treatment. Building their regimens on the Pasteur principle, Hogyes and his followers provide for 3 regimens depending on the severity of the cases, and in each of them, the dosage is increased accordingly in both the basic and additional courses of treatment. The amount of brain tissue that was introduced according to the original Hogyes method equaled from 50.6 to 93.4 mg, and according to Szekely, respectively, 127–195 mg plus 50 to 100 mg for the additional course. The Hogyes method is used, besides Budapest, in a number of other stations where they found it necessary either to replace the Pasteur method with it or to use it in severe cases as an additional course to the Pasteur method. Such stations include stations in Madrid, Buitenzorg (on Java), in Vienna, and other places. Among Soviet stations, this method, significantly modified, began to be used for the first time in 1920 in Astrakhan, in 1921 in Tomsk, and received relatively rapid distribution in those places (Siberia, Caucasus) where one has to deal with severe wolf bites, which most often result in failures during vaccinations and therefore require more intensive methods. The Philipps method is one of the modifications of the Hogyes method. According to this method, the brain is ground in anhydrous glycerin in a ratio of 15 mg of brain to 0.1 cm³ of glycerin. This emulsion, when stored at a temperature of 2–9° in a dark vessel in an oxygen-free space, retains its virulence for several months. For injection, 0.1 cm³ of this emulsion (consequently 15 mg of brain) is taken and 2 cm³ of 1/2% carbolic acid is added to it. Depending on the severity of the bites, from 11 to 19 vaccinations are used. Philipps proceeds to vaccinations with fresh brains only after 3 vaccinations from material previously killed by heating in a 0.5% solution of carbolic acid at 37° for 24 hours. With each such vaccination, 60 mg of brain is introduced. This method was first used by Philipps in Colombia (America) with good results both in experiments and on humans. The main difference between the Philipps method and the Hogyes method is that the vaccine can be stored for a long time, and therefore there is no need to prepare it ex tempore, as is required with the Hogyes method; furthermore, vaccinations begin not with live, but with killed virus; this makes the Philipps method especially convenient. In 1923, when the rabies epizootic intensified in Germany and the demand for vaccinations increased significantly, the Pasteur station at the Koch Institute in Berlin (Baecker) began to use a vaccine that was prepared according to the Philipps principle, but the dosage was built on the principle of the Hogyes method. Here, a basic glycerin emulsion is prepared from the brain and spinal cord in a dilution of 1:10. This basic emulsion is stored for future use and, when used, is diluted 1:25. Vaccinations are conducted according to the following regimen (Table 4). A total of 90 mg of fresh brain is introduced according to this regimen. Treatment is conducted according to an analogous regimen in Breslau. From the same year, 1923, in Berlin, they began to use the indicated vaccine for distribution to branches that were created at that time in Germany in 10 places. The Philipps-Baecker method, like the original Philipps method, gives quite satisfactory results; it is economical, the dosage with it is simple, and it is convenient both for vaccinations on-site and for distribution. The latter is the main reason why it has received relatively rapid distribution at stations in the USSR. In 1930, the largest station in the USSR—the Moscow station—also switched to the Philipps-Baecker method. Fermi's method. With it, a 5% emulsion of brain in a 1% solution of carbolic acid is used. Vaccinations are performed over 15–21–25 days with 5.0–6.0 cm³ for each vaccination. For children, correspondingly smaller doses are dispensed. The author believes that his vaccine, being avirulent, retains its antigenicity, which fits perfectly into the principle of Pasteur's original theory of matiere vaccinale. The works of Babes, Puntoni, Polovandov and Weinberg, Nikolaeva, and others indicate that a 1% solution of carbolic acid does not completely kill the virus in the first days, but only attenuates it or reduces it in quantity, which is also observed with other physical-chemical influences, such as heating, drying over potassium hydroxide, etc. The Fermi method, just like the Hogyes method, is used in various places in Europe, America, and Africa with good results. A number of authors have introduced significant changes to it. In the USSR, this method was first used by Nikolaeva in Ufa in 1921, and then in Omsk. At the present time, it is receiving wide distribution at Pasteur stations in the USSR.

It is most widely used for distribution to Pasteur stations due to the possibility of keeping the emulsion in a sterile state and the ease of dosage. The negative side of this method is that it requires large quantities of brain tissue and that, when it is used, the first vaccinations are often started with virus that has been less preserved in carbolic acid, i.e., more virulent than in subsequent vaccinations. In this regard, Puntoni introduced a very significant correction. He begins treatment with brains preserved in a 1% solution of carbolic acid for 10 days and gradually switches to less preserved ones, bringing the treatment to brains that have been exposed to carbolic acid for one day. In the Puntoni method, the principles of Pasteur are restored again, i.e., he begins with a weaker vaccine and ends with a stronger one. The listed methods, as has already been noted, are systematically replacing the classical Pasteur method at stations in the USSR, which can be seen from Table 5. There are attempts at various stations, especially where severe bites are encountered, to introduce accelerated treatment methods. These include the Remlinger method (Paris, Constantinople), which seeks to finish vaccinations within a five-day period, giving 4-6 vaccinations per day according to the following scheme (Table 6): which is then preserved in glycerin; he conducts treatment over 5 days with 2-3 vaccinations per day. Depending on the severity of the case, from 2 to 3 g of brain tissue is introduced. The only drawback of both these methods is that the vaccinations are painful. The Alevisatos method is used in Vienna in severe cases as an addition to the main treatment method (the Högyes method). Babes, Marie, Remlinger, Fermi, and others proposed using antirabic serum obtained from immunized virus fixe animals (goats, horses, cows, etc.). Later, the authors came to the conclusion that the effect of this serum is more effective when it is used as a serovaccine, i.e., a mixture of inactivated antirabic serum with virus fixe. This allows for the immediate introduction of a large amount of fresh virus fixe. Starting from 1903, Marie introduced the use of serovaccine at the Paris Pasteur Institute for the treatment of severe cases. Vaccinations with serovaccine precede the usual vaccine treatment, which begins immediately with virulent brains. In this way, they sought to accelerate treatment, make it more intensive, and less dangerous. At some stations in the USSR (Leningrad, Saratov, Samara, Perm, Tashkent, Ufa, Dnepropetrovsk, etc.), in cases of severe bites, serum was also used in pure form or in a mixture with the vaccine as an addition to the vaccine. No one except Fermi (the latter reports 0% mortality) notes any encouraging results from serum treatment, either in the USSR or abroad. Complications with antirabic vaccinations. Antirabic vaccinations sometimes cause complications of a local and general nature. Among local phenomena, redness, edema, itching, and pain at the injection site are observed; for reasons not yet understood, these phenomena occur most often on the 7th-10th day after the start of treatment. Among complications of a general nature, the most significant are disorders of the nervous system. They are of a very diverse nature—from mild paresis of the facial nerve and oculomotor nerve to Landry's ascending paralysis and meningomyelitis inclusive. Regarding the causal link between paralysis and vaccinations, there is a number of theories. Some (Roux and others) categorically reject the role of virus fixe in these complications. I. Koch explains these complications by the action of street virus, but weakened as a result of vaccinations. Schweinburg and Kraus attribute these complications to the toxic substance of the nervous tissue. Ushakov believes that the infection is connected with a spontaneous virus that happened to be in the rabbit brain taken for the preparation of vaccines. Along with this, the majority of authors acknowledge that the complication of the nervous system should be linked to virus fixe, but give this fact a different explanation. Thus, Babes, Remlinger, and others believe that intoxication by the rabies virus plays a role here; Kotsevalov, Pfeiffer, Toporkov, and others blame virus fixe directly for this, which can cause this kind of infectious disease. The material that is accumulating at stations in the USSR speaks most in favor of the fact that paralysis must be linked to virus fixe. In 1927, 20 cases of paralysis were registered at 9 stations, with myelitis, myeloencephalitis, and paraplegia being noted, as well as transient paralysis of individual central nerves. Among these cases, there are persons who received bites from healthy animals, and there are also persons who received vaccination due to being licked. It is noteworthy that at some stations the number of nervous complications increased with the transition to a more intensive method and the use of fresh brains. The same was noted in Weltevreden on Java and at one time in Berlin and other places. It is essential to establish what the role of one or another method is in the development of these nervous phenomena. The material from USSR stations indicates that complications can occur with all methods. They were observed in Moscow and Dnepropetrovsk, where the Pasteur method was used; in Leningrad, where the Fermi method was used; in Kiev, where the Högyes method was used; and in Irkutsk, where the Remlinger method was used. Fortunately, these complications are quite rare, approximately 1 time per 5,000-10,000 cases. The advantages of one or another method should be evaluated in the same way. However, the methodology of accounting encounters extremely great difficulties, since mortality depends on a number of factors: 1) on the severity and extent of the bites; 2) on their localization (bites to the head result in a mortality rate 5-7 times higher than the average mortality); 3) on the type of animal that bit (wolf bites are 25-30 times more dangerous than dog bites; the latter are 2-3 times more dangerous than cat bites; mortality among those bitten by herbivorous animals is completely negligible); 4) on the time of appearance for treatment, etc. Despite these difficulties and sometimes inaccuracies in the accounting of results, a number of data from different countries indicate that the average total mortality among those treated is 0.8%, and the reduced mortality is 0.39%, with the former fluctuating in various institutes from 0.25% to 1.23%, and the latter from 0.16% to 0.83%. At stations in the USSR, it has remained at the level of 0.2-0.3% in recent years, and the reduced mortality is 2-3 times lower. In 1927, the total mortality among bitten vaccinated persons (those licked are excluded) was 0.24%, and in 1928, 0.19%. The relatively small percentage of mortality at stations in the USSR, despite the presence of wolf bites, is partly connected with the fact that 2/3 of all those treated belong to the 3rd category, i.e., persons who received bites from animals only suspected of having rabies, and among them, there were likely those treated who did not need vaccinations. Comparing the mortality data among the treated and untreated, the authors come to the conclusion that the effectiveness of antirabic vaccinations is undoubtedly great. On average, it should be considered that vaccinations reduce mortality by no less than 8-10 times. As for the question of which of the methods gives the best results, the material from Soviet stations for 1927-28 and incompletely (27 stations) for 1929-30 provides the following numbers (Table 7):

Pasteur Method: 1927: 0.20, 1928: 0.11, 1929: 0.05, 1930: 0.09; Fermi Method: 1927: 0.16, 1928: 0.07, 1929: 0.12, 1930: 0.12; Högyes or Phillips Method: 1927: 0.12, 1928: 0.10, 1929: 0.11, 1930: 0.06; Pasteur-Fermi Method: 1927: 0.33, 1928: 0.60, 1929: 0.10, 1930: 0.12; Phillips-Fermi Method: 1927: -, 1928: 0.10, 1929: 0.20, 1930: -. These figures refer to the mortality rate per treated patient. Although these figures are low for the vaccinated, they still suggest that rabies vaccinations, in which live poison is introduced into the human body along with brain tissue from a sick animal, should not be considered indifferent for humans, and in cases where vaccinations are absolutely not necessary, they should not be prescribed. At most stations in the USSR, the Panisset and Verge scheme is adopted, according to which indications for vaccinations are established (see Rabies). Mortality from rabies among the vaccinated and unvaccinated. Since the main task of Pasteur stations is to prevent the disease among those bitten by rabid animals through vaccinations, the effectiveness of vaccinations can be judged by the mortality from hydrophobia among the treated, on the one hand, and the untreated, on the other. Combined treatment is usually used in severe cases, which explains the somewhat increased mortality with it. Data from USSR stations generally speak in favor of dilution methods. They also speak in favor of the work of anti-rabies centers, since the Fermi and Högyes-Phillips methods are predominantly used there. True, at the centers, for the most part, people who have received minor bites are treated, since those with severe bites are as a rule sent for treatment to Pasteur stations. Preventive vaccinations for animals. From the first experiments of Pasteur (and even before him from the works of Galtier) it is known that by means of preventive vaccinations it is possible to prevent the disease of rabies in animals infected with this disease. For the purpose of prophylactic immunization of animals, Pasteur's methods and dilution methods (Aujeszky) were used. Attempts were made to protect animals from contracting laboratory rabies by injecting the vaccine into the abdominal cavity (Gelman, and later Marx, Pokshishevsky, et al.), intravenously (Galtier, and later Roux, Babes, et al.), and by intravenous injection of material heated to 37° and filtered (Krasnitsky, and later Remlinger, et al.); serovaccination was also used (Marie, Remlinger, et al.). All these experiments did not always yield satisfactory results. Immunity is more persistent when large quantities of active virus are introduced, but this, for its part, causes the immunized animal to contract laboratory rabies. This circumstance, as well as the fact that anti-rabies vaccinations are expensive, long-lasting, and sometimes complex, prevented them from entering practice for animals. The recently proposed so-called Japanese method (Umeno, Doi) (see Rabies) is free from a number of shortcomings that have hitherto hindered the use of anti-rabies vaccinations in animals: with it, killed material is introduced, consequently the danger of direct infection is avoided, the treatment is short-term, and it protects well against further diseases from street rabies. This method has been tested in various places and gives very encouraging results. This is evidenced by the large amount of material from the Japanese (Hata et al.) and Americans (Eichhorn and Lyon), covering a total of about 200,000 dogs, as well as experimental data from a number of authors. Objections to this method are also found in the literature (Fermi). There is no doubt that for the elimination of rabies, the only true method remains, at the present time, as before, the extermination of wolves, the destruction of sick animals, and veterinary-sanitary and police supervision of the carriers of this virus—dogs (see Rabies).