Vaccination (VACCINES)

VACCINATION, VACCINES. Vaccination (from the Latin vacca - cow; hence vaccine - cowpox) is a method by which an organism is artificially given increased resistance to any infection; the materials used for this purpose are called vaccines. Jenner, by transferring the virus of human smallpox from calf to calf, achieved a weakening of the virus in its virulence to such an extent that when reintroduced to humans, it caused only a local pustule (see Scab); thus Jenner obtained the first artificial vaccine and discovered one of the methods for weakening the virulence of disease agents. Pasteur followed this path, developing techniques for weakening the virulence of various infectious agents and preparing several vaccines (anti-rabies, anthrax, chicken cholera, etc.). At present, the name "vaccine" is usually given to any material used for preventive inoculations against infectious diseases, whether this material consists of living, fully or weakly virulent, or of killed infectious agents, or finally, of products of their vital activity or artificial breakdown. Vaccines can be divided into the following groups, or types: 1) consisting of living, fully virulent agents of disease; 2) of living agents, the virulence of which has been artificially weakened to the desired degree; 3) of living, fully virulent agents, treated with specific inactivated bactericidal serum (sensitized vaccine); 4) of disease agents killed by high temperature or chemical substances; 5) of killed disease agents with the addition of a certain amount of inactivated specific serum (serovaccine); 6) of products of the vital activity of microbes or their derivatives (for example, toxins, autolysates of microbes, tuberculins, etc.).-If a vaccine contains the agent of only one disease, it is called a monovaccine; if it contains two different agents - a divaccine, three agents - a trivaccine, four agents - a tetravaccine, five agents - a pentavaccine. Vaccines with more than five different agents are used very rarely. Complex vaccines, composed of several agents, are used when it is necessary to give the organism resistance to several infections in as short a time as possible. However, it should be borne in mind that the simultaneous introduction of several antigens gives a smaller immunizing effect than that obtained when immunizing with one antigen. Therefore, to achieve a higher degree of immunity, it is preferable to use a monovaccine. For the preparation of monovaccines, not one, but several strains of the same type of microbes, isolated from many cases of identical disease, are used, taking into account the possibility of individual variations in the antigenic properties of individual strains. Such vaccines are called polyvalent, in contrast to monovalent vaccines, which are prepared from one strain. Vaccines prepared from microbes isolated from the same patient on whom they are applied are called autovaccines, in contrast to heterovaccines, prepared from strains isolated from other patients. The importance of polyvalent vaccines is evident from the firmly established fact that some microbes, such as pneumococcus and meningococcus, are divided into several sharply distinct serological types, having such different antigenic properties that the antibodies produced by each are active only against the corresponding types of microbes. Therefore, a vaccine prepared from meningococci of type A can protect against infection with type A meningococcus, but not type B, and vice versa. The change in the biological and antigenic properties of microbes (streptococci, bacilli of the typhoid-enteric group, etc.) under the influence of the action on them of the host organism, individual tissues and organs, physical and chemical factors (Meyer, Petruschky, Rosenow, Zlatogorov and many others) is also a firmly established fact. On the other hand, autovaccines find preferential application in vaccine therapy (see Autovaccine). For the preparation of vaccines, pure 1-2 day cultures of microbes are used. Usually agar cultures are used, more rarely broth cultures. The deposits of microbial masses formed on the surface of nutrient agar are washed off with a physiological solution of table salt (0.85% solution of chemically pure sodium chloride) and diluted with it in such a way that in 1 cubic cm of the resulting suspension the required number of microbes is contained (usually from one hundred thousand to one and several billions in 1 cubic cm of suspension). For practical purposes, it is quite sufficient to establish the proper concentration of the vaccine by comparing the turbidity of the prepared vaccine with available samples containing in 1 cubic cm a precisely determined number of microbes. Such samples are called standards. In the USSR they are produced and distributed by the State Serum and Vaccine Control Institute in Moscow. If it is necessary to count the microbes contained in a given suspension (vaccine), it is convenient to use the following method of Wright (Wright), in the modification of Korshun and Timofeev: blood is taken from some animal, defibrinated, and its formed elements are freed from serum by repeated centrifugation and washing in a physiological salt solution. Then the number of red blood cells is counted exactly, and the blood is diluted so that in 1 cubic cm there is a certain number of them, for example, 1 billion. After this, 1% formalin is added, and the number of red blood cells is checked again. In this form, blood is preserved for a very long time without a significant change in the number of erythrocytes. To count microbes, the following procedure is followed: formalinized blood is mixed in certain proportions with the vaccine. From the mixture, smears are prepared on glass slides, fixed, stained (according to Giemsa, thionine, a mixture of eosin with methylene blue, etc.), and counting is done in several fields of view (at least 20 fields) of both erythrocytes and microbes separately. Then it is calculated how many microbes, on average, fall on each red blood cell. Thus, knowing the number of the latter in 1 cubic cm, it is easy to determine the amount of microbes in 1 cubic cm of a given vaccine. Vaccination with living infectious agents belongs to the oldest methods of conferring immunity to an organism. Thus, the Chinese as early as the 900s artificially induced a mild form of smallpox by inoculating people with material from dried smallpox pustules. The living virus gives the organism a more durable and lasting immunity. However, this method has major disadvantages, especially when applied to humans. Indeed, it is associated with the danger of causing severe (and even fatal) disease in the vaccinated person, there is a danger of the spread of infection by the vaccinated, and finally, it is very difficult to have a vaccine of constant virulence, which makes accurate dosing impossible. A great inconvenience is also that the live vaccine must be prepared ex tempore, as it cannot be kept for a long time in a ready state. In view of the above, virulent live vaccines are rarely used for vaccinating people. Of vaccines of this type, the cholera vaccines of Ferran and Haukin should be mentioned first, although these vaccines now have only historical interest. The Spanish researcher Ferran seeded nutrient broth with cholera excreta and obtained mixed cultures in this way, containing, in addition to fully virulent cholera vibrios, many foreign bacteria from the intestinal flora, which he injected under the skin of people. It is clear that this method could not gain general acceptance and was soon abandoned. The Russian physician Haukin, guided by the ideas of Pasteur, prepared two vaccines from cholera vibrios with different virulence. For the first vaccination, cultures of cholera vibrios were used, the virulence of which had been weakened by prolonged cultivation at 39° with constant passage of oxygen; for the second, cultures whose virulence Haukin tried to bring to a maximum by constantly passing them through the organism of guinea pigs. For injection into adults, Haukin took 10-day and 17-day cultures on slant agar. A week's break was made between each injection. Haukin's vaccines, which gave generally good results when tested on several tens of thousands of people in India, were abandoned because they have no advantage over vaccines from killed microbes (see below), while their preparation is more complex. Among other vaccines, the anti-rabies vaccine of Hódyes is now quite widely used, prepared from freshly taken fully virulent brain of a rabbit that died from fixed virus (see Rabies).

This category also includes sensitized live vaccines of Bezredka, prepared from virulent 1-2-day-old typhoid, dysentery, and other agar cultures as follows: the bacterial masses are washed from the surface of the agar with a physiological salt solution, the corresponding bactericidal serum is added (to typhoid bacteria - typhoid serum, etc.), and the mixture is placed in an incubator at 37° for 1-2 hours. Then the bacteria are precipitated by centrifugation, the liquid is poured off, and the bacteria are repeatedly washed with a physiological salt solution. From bacteria treated in this way with specific serum, a vaccine is prepared in the usual manner. But although sensitized vaccines contain live and virulent bacteria, they cannot be equated with fully virulent material, since treatment with specific serum significantly weakens the aggressiveness of the bacteria, why sensitized bacteria are easily phagocytosed and dissolved in the body's juices, causing only a weak local reaction. In recent times, Böme (Böme, 1926) proposed to immunize against diphtheria by rubbing fully virulent diphtheria cultures into the skin. But this method has not yet found supporters. Vaccination with live, unattenuated virus is quite common in veterinary practice, as it appears economically advantageous to tolerate some 'loss' of animals in order to achieve a higher and longer-lasting immunity (see below - vaccination of animals). Vaccines prepared from live but attenuated pathogens are used much more widely. The prototype of such vaccines is Jenner's smallpox vaccine. The methods developed by Louis Pasteur form the basis for preparing this type of vaccine. Of these, the following methods are most important: 1. Attenuation by high temperature. In this way, the anthrax vaccine of Pasteur, Tsenkovsky, and Lange was obtained (see below - vaccination of animals). The anti-rabies vaccine according to Babes is prepared by heating an emulsion from the brain of a rabies-infected rabbit at 56-58° for various periods of time, from 2 to 40 minutes (see Rabies). The vaccine against malignant edema (according to the London method) is prepared from the muscle juice of dead animals, with the first vaccine (weaker) being heated for 6 hours at 100-104°, and the second vaccine for 6 hours at 85-90°. 0.1-0.2 g of dry substance of the juice is injected. - 2. Attenuation by drying was first used by Pasteur to prepare his classic anti-rabies vaccine. - 3. Attenuation by chemical substances, of which it is necessary to mention the following: trypaflavin and erythrosin, used by the Japanese researcher Shiga for attenuating tuberculosis cultures; the latter are grown for a long time on liquid nutrient media with the addition of increasing amounts of these substances; further, a 25% solution of urea: tuberculosis bacilli are shaken in this solution for 5-7 1/3 days at 37°; 80% glycerin: 5 mg of tuberculosis or glanders culture is taken per 4 cubic cm of glycerin and shaken for 24 hours at 37°, with the virulence of the tuberculosis bacilli being weakened 2,500-5,000 times; alcohol is added in amounts from 0.5% to 5% to the broth, into which plague bacilli are then seeded; by combining different amounts of alcohol with temperatures from 40 to 43°, Kolle and Otto obtained almost avirulent plague cultures with high immunizing properties. - Special attention deserves the attempt of Calmette to use a live tuberculosis culture known as BCG (Bacilles Calmette-Guerin; see Bacteria) as a vaccine. - 4. Attenuation of the virus by passage through the bodies of certain animals, for example, passage of smallpox virus through calves, swine fever through rabbits, trypanosomes of cattle through rats and then through dogs, trypanosomes of the causative agents of hemoglobinuria in cattle through calves, etc. Vaccination with killed microbe cultures. Through classical studies by Salmon, Smith, Chamberland, Roux, Pfeiffer, Isaev, and Wassermann, it was proven that immunization with killed cholera cultures confers increased resistance to infection with live cholera vibrios to various species of animals. Furthermore, Pfeiffer with his colleagues established that in immunized animals, the bactericidal action of their blood serum on cholera vibrios is increased. The same change in blood properties is also observed in people who have had Asian cholera under natural conditions. Thus, a direct connection is established between the enhancement of the bactericidal action of the blood and the immunity resulting from immunization with killed cholera cultures. Based on these observations, Pfeiffer and Kolle proposed vaccines from killed cholera vibrios, typhoid bacilli, etc., killed by heat. The Pfeiffer and Kolle vaccine was successfully used on a very large number of people both in the period from 1902 to the imperialist war, and especially during the latter war (see Typhoid fever, Cholera, etc.). To kill microorganisms, either high temperature or the addition of disinfectant solutions is used. Bacteria are killed at the lowest possible temperature. The following table shows the most suitable temperature and duration of heating for preparing various vaccines. Bacteria Species Temperature Duration In what cultures prepared Typhoid bacillus Dysentery bacillus Plague bacillus Fowl cholera bacillus 58° 56-58° 55° 65° 4 2-4 3° 1 hour 1 2

After heating, the sterility of vaccines is checked, and then 0.5% phenol is added to them to prevent the growth of foreign microbes. Of chemical substances, only those are used which, while killing microbes, do not impair their antigenic properties and are not harmful to the human organism. The most commonly used of these are the following: phenol 0.5%, formalin 0.05-0.1%, tricresol 0.5%, ether, trypaflavin, yatren, ehinacin, vutsin, and others. Formalin is especially suitable, which is added to liquid cultures; sometimes, mainly on solid media, microbes are killed by formaldehyde vapor. In this case, the death of microbes occurs in a short time, and subsequently the process of autolysis is eliminated, thanks to which the vaccine for a very long time preserves unchanged its appearance and its antigenic properties. The following vaccine, recently used in Japan, is very suitable. To bacterial cultures washed from agar and 1-2 days old, a specific bactericidal serum is added according to a certain calculation, and the mixture is placed for 2 hours at 37° for the sensitization of bacteria; then 0.5% phenol is added (Takapo, Ohtsubo and Inouye). As can be seen from the above, this serum vaccine has much in common with Bezredka's sensitized vaccine (see above). Due to the presence of serum in it, it is less toxic than ordinary vaccine and gives a smaller reaction. Some recommend so-called lipovaccines, which are a suspension of microbial bodies in liquid oil. Due to slow absorption, lipovaccines form a depot in the body, from which the antigen slowly enters the bloodstream. Hence the long-lasting immunizing effect of lipovaccines. Autolyzed microbial bodies are also used as vaccines, but such vaccines cause too strong a reaction, which hinders their widespread use. For the preparation of vaccines, microbes isolated during the current epidemic are preferably used. The dosage of vaccines is very diverse and partly depends on the endotoxicity of the microbes contained in them. It ranges from several tens of thousands of microbial bodies to several hundred thousand and even up to several billion (1-1 billion in cholera vaccine) per injection. When choosing the dose of vaccine, one should be guided by the general rule that the local and general phenomena caused by injection should, as far as possible, be absent or weakly expressed, without taking the body out of its normal state. A weak or moderate reaction in no way harms immunization, and at the same time indicates that the dose of vaccine was chosen correctly, achieving the maximum amount of antigen well tolerated by the body. However, an infiltrate at the injection site, an increase in temperature, and other phenomena of reaction to the introduction of vaccine cannot be considered necessary for the development of immunity: the body can acquire immunity without any visible reaction to the injection of vaccine. Repeated fractional administration of vaccine with short intervals gives a better effect than a single administration of large quantities. Moreover, as Wright proved, large doses of vaccine give a deep negative phase, i.e., a significant temporary decrease in the available amount of antibodies in the blood, which only slowly equalizes to normal in order to then exceed it (see Active immunization). Small doses, however, do not give a negative phase, or it is shallow and transient (see Vaccinotherapy). Taking into account the practical inconveniences associated with multiple injections, it is recommended to choose the dosage of vaccine so that the amount necessary to give the body sufficient immunity is administered in 2-3 doses. The intervals between injections are set at 5-7 days, but in some cases they can be shortened to 2-3 days or extended to 14 days. The next injection of vaccine is given only after the local and general reaction has subsided; when determining the dose, one should be guided by the strength of the reaction. In recent times, Bezredka proposed for immunization per os a dry vaccine in the form of tablets. The tablet contains 100 billion killed and dried bacteria. The tablets are taken on an empty stomach, one hour before meals, one at a time, three times, every other day. So far, cholera, typhoid, paratyphoid, and dysentery tablets have found application. Before taking the tablet, a pill of bile is taken, since bile, in Bezredka's opinion, facilitates the access of bacterial bodies to the intestinal wall. Only dysentery tablets are taken without bile, since they themselves increase its secretion into the intestine. Based on this, V. I. Nedrigailov advises to replace bile with the addition of dysentery bacilli to the composition of typhoid and other tablets. Some authors recommend taking cocoa as a constituent for pills, which, according to I. P. Pavlov, has a choleretic effect. In addition to tablets, for immunization per os (according to Zabolotny) a liquid vaccine is used, with the dosage remaining the same, i.e., 100 billion bacteria per dose. For immunization against scarlet fever, Gabrichevsky's streptococcal vaccine has long been used. In recent times, a combined vaccine has been proposed, consisting of a certain amount of hemolytic streptococcus (from 1 to 3 billion in 1 cubic cm) and scarlatinal streptococcal toxin (2,000-5,000 skin doses in 1 cubic cm). Three injections of vaccine and one of toxin are given (details see Scarlet fever). Toxins as material for vaccination have found very wide application in recent years. To avoid a sharp reaction in particularly sensitive subjects, toxins are converted into toxoids by treatment with formalin according to the Ramon method (see Anatoxin). Diphtheria toxoids are very suitable for immunizing people against diphtheria. For the same purpose, in addition to toxoids, mixtures composed of toxin and corresponding antitoxic serum are used. The latter method is widely practiced in the U.S.S.R., where the number of children immunized with mixtures exceeded one million in 1927. In the U.S.S.R., two kinds of mixtures are mainly used: the American one, more toxic but at the same time more diluted, and the neutral one of S. Korshun (see Diphtheria). It should also be mentioned about filtrates of broth cultures of various bacteria (Bezredka's antiviruses), which are used less for preventive than for therapeutic purposes in the form of compresses, wet tampons, and injections for various lesions of the skin, mucous and serous membranes and cavities (see Antivirus). The negative phase after vaccine injection was first noted by the English researcher Wright. He noticed that after the administration of vaccine, the opsonic index (see Opsonins) decreases and then gradually increases again, reaching its original level and even exceeding it. The negative phase, in Wright's opinion, signifies a decrease in the amount of protective substances in the body and indicates a decrease in its resistance to infection during this period. From this it is concluded that vaccination is dangerous in foci of infection and at the height of an epidemic, because, due to the negative phase, the body becomes an easier victim of infection. But numerous observations on vaccination against cholera, typhoid fever, diphtheria, scarlet fever, etc. have shown that the negative phase does not have a significant effect on the degree of immunity and that its importance is greatly exaggerated. Indeed, it can be admitted that the administration of vaccine in the incubation period can, apparently, accelerate the manifestation of the disease (provoke it), from which, however, the severity of the disease does not increase. In addition to specific vaccines, which contain the causative agents of the diseases against which immunity is desired to be conferred, non-specific vaccines are sometimes used, namely in those cases when it is desired to quickly raise the general resistance of the body. Among many types of non-specific vaccines, one can mention as an example Much's vaccine, composed of several species of non-pathogenic bacteria, proteins of non-bacterial origin, and lipoids (explanation of the action of non-specific vaccines see in the article Proteinotherapy).

S. Korshun. Vaccination of animals. In the fight against epizootic diseases of domestic animals, vaccination of the latter has taken on the widest dimensions and is currently in the USSR the main preventive measure, along with general veterinary-sanitary measures. Vaccination of animals can be carried out either for the purpose of preventing the appearance of an epizootic (preventive inoculations) or for the purpose of stopping, terminating an existing epizootic (forced inoculations). Often, however, the task arises of creating an immediate, active immunity among animals, and then resort is had to a mixed, combined method of inoculations, i.e., to the injection of both vaccine and serum into the animal at the same time. For the purpose of obtaining passive immunity, i.e., immediate but short-term protection of animals against infection with a specific infectious disease, only specific serum is administered in its pure form. 1. Anthrax. To prevent its spread among animals and also to stop it, Louis Pasteur first produced two anthrax vaccines—the first and second. The first has negligible pathogenic strength; it should kill only mice and part of the susliks or very young guinea pigs; when inoculated into agricultural animals, it rarely causes a tumor (or fever) at the site of inoculation. On the contrary, the second vaccine, when inoculated, should kill all mice, all adult guinea pigs, and no more than 7* rabbits; agricultural animals react to the injection of the second vaccine both with temperature and with the formation of an anthrax carbuncle at the injection site; the percentage of severe diseases after inoculation with the second vaccine sometimes rises to 5; the mortality from inoculations in sheep and horses is expressed as 0.3%, and in cattle—0.05% of the total number of vaccinated animals. The basic principle of producing anthrax vaccines according to Pasteur is based on the property of the anthrax microbe not to form spores at a temperature above 42.5°; its bacillary form, at such a temperature, although it multiplies, gradually loses its virulence and, after 20 days of growth in an incubator, becomes equal in strength to the first vaccine, and after 10-12 days of cultivation equal in strength to the second vaccine. In the USSR, vaccines of Tsenkovsky are widely used and, to a lesser extent, Lange. They are prepared independently by Pasteur's method. However, Tsenkovsky as early as the 1890s indicated a method for converting bacillary vaccines into spore form, a method for preserving them in glycerin solution, and a method for fixing the degree of their virulence. Vaccination of animals against anthrax annually covers over 2 million head in the USSR. By combining methods of inoculation, the goals of both prevention and suppression of anthrax epizootics are achieved. For livestock that die from anthrax after inoculation, the state pays the owners of the animals monetary compensation. The production of anthrax inoculations is regulated by a special instruction issued by the Veterinary Administration of the People's Commissariat of Agriculture of the RSFSR. Vaccines are currently administered by the Besredka method—intracutaneously. Dosage of Tsenkovsky vaccines. For adult horses and cattle: first vaccine—1.0; second vaccine for horses—0.3, for cattle—0.3-0.5; for adult pigs: first vaccine—0.5, second—0.2; for adult sheep: first vaccine—0.2 and second—0.1; for foals and calves under 2 years: first vaccine—0.3-0.5; second—0.1-0.2; for pigs under 2 years: first vaccine—0.3 and second—0.1; for sheep under 2 years: first vaccine—0.15 and second—0.1. Dosage of Lange vaccines. For adult horses and cattle: first vaccine—1.0 and second vaccine—0.75; for foals and calves under 1 year: first vaccine—0.5 and second—0.3-0.4. The second vaccine is injected on the 10-12th day after the first. Dosage in combined inoculations: for adult horses and cattle: serum—10.0 and second vaccine—0.3; for young stock under 2 years (respectively)—6.0-8.0 and 0.1-0.2; for sheep (respectively)—4.0-5.0 and 0.1. Preventive inoculations with serum in doses: for horses—10.0-20.0, for cattle—10.0 and for sheep—5.0. 2. Rabies in dogs and other domestic animals. As a preventive measure, anti-rabies vaccine is administered to agricultural animals, both bitten and unbitten; the latter is prepared for them in the USSR in the form of a thin emulsion according to the Krasnitsky method (1.0 virus lixe and 300.0 physiological solution of NaCl) and is injected only twice subcutaneously in doses of 50.0, with an interval of 5-7 days between the first and second injections. In Western European countries, the vaccine is administered to agricultural animals either by a modified method of Hedges or by the Remlinger-Alivizatos method (virus lixe is weakened by the action of sulfur ether for 72-96 hours). It is recommended to vaccinate bitten agricultural animals no later than 10 days after the bite. Aujeszks successfully vaccinated 9,328 agricultural animals by the Hedges method; of 8,851 animals vaccinated in a timely manner, only 46 subsequently died from rabies, i.e., 0.51%. Even of 427 animals severely bitten by dogs known to be rabid, only 22 became ill after vaccination, i.e., 5.1%, whereas in such cases, unvaccinated animals usually die from rabies 30-90%. In the last decade, in Japan and America, preventive inoculations of dogs (unbitten) have been introduced by legislative acts. The material for them is anti-rabies vaccine prepared by the Umeno and Du method. For this purpose, the spinal and brain of a rabbit that died on the 7th-9th day are taken and ground for 1 hour with 5 parts of carbolic-glycerin solution (60 parts glycerin and 40 parts 1.25% solution of Ac. carbolici); after filtration through gauze, the emulsion is left for 14 days at a temperature of 20-22° to weaken it. The inoculation is done subcutaneously once, on the chest or back, in a dose of 3.0-5.0. Puppies younger than 4 months are not vaccinated. In Europe, preventive inoculations of dogs (unbitten) were carried out by the methods of Umeno and Du, Misner, Baars, Alivizat^s, and Michii—only in laboratories. The World Congress on Rabies in 1927 expressed itself in favor of allowing such inoculations for dogs, provided they are observed for 4 months. Dogs that are bitten by animals suspected of having rabies can also be vaccinated, but then must be kept in isolation for 6 months. 3. Foot-and-mouth disease in cattle, pigs. Preventive inoculations with saliva and blister fluid from animals sick with foot-and-mouth disease (in a benign, mild form) are widely practiced in the USSR. In Germany, in the last decade, serious attention has been paid to the production of anti-foot-and-mouth disease serum in large quantities by the Loeffler-Frosch method. The latter has both therapeutic and preventive properties; therefore, it can be used in its pure form for therapeutic purposes in humans and animals suffering from foot-and-mouth disease; in the latter, it is also injected with the aim of creating a short-term (for 2-3 weeks) passive immunity or by the combined method of inoculation (serum and virus) to obtain a prolonged (for several months) active immunity. The high cost of anti-foot-and-mouth disease serum limits the scope of its application in other countries. 4. Abortion in cows. To stop this epizootic, preventive inoculations with either killed or live cultures of Bac. abortus Bang are recommended; in Germany, in farms where abortion among the existing cows exceeds 50%, vaccination of animals with live cultures is permitted by law; in the USSR, vaccination of cattle against abortion is not yet widespread. The cultivation of cultures is associated with difficulties and requires a specially freshly prepared nutrient medium; for this purpose, 1 liter of water is taken for 400 g of finely chopped meat (cattle); this mixture is left to stand for a day; then 3.0 NaCl, 2.0 Natr. biphosphorici are added, and it is boiled; then it is filtered and 10.0 peptone, 10.0 grape sugar, and 25.0 glycerin are added; the reaction of the medium should be weakly alkaline; pH—7.3-7.5. Cultures are grown for 10-14 days. They are killed either by heating to 60° in a water bath for 1-2 hours or by adding disinfectants (Ac. carb. 0.5%, formalin—0.1-0.2%). Agar-agar medium can also be used for cultivating Bac. abortus Bang. Vaccination is done several times with 2-4 week intervals. After the 6th month of pregnancy, no inoculations are given. 5. Abortion in mares. Inoculations are used with killed cultures of the causative agent that caused the epizootic (most often Bac. abortus equorum Polyakov or Streptoc. abortus equorum). 6. In glanders of horses, foals are vaccinated for preventive purposes with specific anti-streptococcal serum in doses from 60 to 100.0; however, the immunity is short-lived (2-4 weeks). The combined method of inoculation (extract from cultures and immunizing serum) gives a more stable and prolonged immunity (for 8-16 months). 7. Pneumonia in cattle. The preventive inoculations with live vaccines used are not very effective; they are practiced only in backward or poor countries (in richer countries, as a radical measure, resort is had to the method of mass slaughter). 8. Rinderpest. To stop it, simultaneous inoculations (specific) with serum from the defibrinated blood of an animal sick with rinderpest are successfully carried out (since the causative agent—an invisible virus—has not yet been obtained in cultures).

The dose of plague virus--1.0 cubic cm, is used simultaneously with anti-plague serum, calculated at 4.0 per 16 kg of live weight; for cattle and cultural breeds, the serum dosage is increased 2-3 times.-9. Swine plague. The fight against it is based on the preventive use of specific serum: to obtain at least a brief, passive immunity (three to four weeks) or to achieve active immunity (for at least six months), swine are subjected to simultaneous vaccination (serum and plague virus). The virus dose is from 0.25 to 1.5. Serum doses by weight in simultaneous vaccination: from 5 kg to 20 kg of animal weight-10-30 cubic cm, up to 40 kg-up to 40 cubic cm, up to 60 kg-up to 50 cubic cm, up to 80 kg-up to 60 cubic cm- 10. Swine erysipelas. The fight against it is carried out either with vaccine vaccinations or simultaneous injection of specific serum and virus (or 2nd vaccine). The method of manufacturing swine erysipelas vaccines is based on the biological property of the disease agent Bac. rhuslopathiae suis to partially lose its virulence when passed through the body of a rabbit. Cultures passed through 7 rabbits significantly weaken in their virulence and serve as the 1st vaccine; in swine they cause only very mild illness; the 2nd vaccine consists of cultures passed through 3 rabbits. In recent years, a combined vaccination method (2nd vaccine or culture of swine erysipelas bacillus mixed with serum) has found wide application. In its pure form, one anti-erysipelas serum is injected either if it is desired to immediately stop the epizootic or for therapeutic purposes. In Germany in recent years, the skin method of vaccination has been finding application. Dosage of erysipelas vaccines: for adult swine-1st and 2nd vaccines 0.2 each, for piglets both vaccines 0.1 each.- 11. Fowl cholera. It is suppressed by the use of killed or weakly virulent cultures or by injection of specific anti-cholera serum. Doses of avirulent cultures: 1.0 for chickens, 2.0 for geese, turkeys and ducks. Dosage of anti-cholera serum: chickens: healthy 3.0-4.0, suspicious 6.0-8.0, sick 8.0-12.0; ducks (respectively): 4.0-5.0, 8.0-10.0, 10.0-15.0; geese and turkeys (respectively): 5.0-6.0, 10.0-12.0, 12.0-18.0. The serum is injected either into the muscle tissue or under the skin of the nape; so that the feathers lie flat and do not hinder the injection, they are moistened with either a carbolic acid solution or alcohol.-12. Sheep pox sometimes rages among sheep farms; compulsory protective vaccination of sheep (ovinatio), in unfavorable or threatened areas, usually proceeds more favorably than natural infection; ovination gives vaccinated sheep stable immunity, however, the vaccinated flock still represents a focus of infection; therefore, resort to immunization of sheep by means of a virus weakened by one method or another. Koniev proposed to weaken ovination by passing it through the body of a goat and in this way obtained vaccination material called "caprina". Bridre and Boquet impregnated (sensitized) the sheep pox virus-pulp from pustules-with highly virulent specific serum, and then centrifuged and triturated the precipitate with a physiological NaCl solution (2:100). Such an emulsion is injected subcutaneously into sheep in a dose of 0.25; immunity develops already after 48 hours and lasts for at least 5 months. Borrel advises producing simultaneous vaccinations: immunizing serum (5.0-15.0) under the skin of the body and virulent lymph (0.05) on the ear.-13, Emphysematous carbuncle of cattle. Vaccination of cattle with weakened cultures is now completely replaced by vaccinations with filtrates from broth cultures Bac. sarcophysema-tos bovis (Chauveau) or aggressins; filtrates are used subcutaneously in doses of 5.0-10.0, while aggressins in a dose of 1.0-3.0. Vaccination with aggressins or filtrates gives immunity for 5-12 months; mortality from vaccination is negligible (0.065-0.1%).- 14. Tetanus is a relatively rare disease in animals; therefore, the fight against this suffering by preventive vaccinations with specific antitetanic serum is required only in those areas where tetanus is a frequent post-wound complication. In the developed form of the disease, serum is of little effect; however, the earlier treatment with serum is started, the better the results from its use. Conversely, as a preventive measure, vaccination with antitetanic serum after dangerous wounds definitely saves animals from subsequent tetanus infection.