How the vaccine is obtained. On the shelves: vaccines - what, when, to whom. National vaccination calendar

Vaccines (Latin vaccinus cow)

preparations obtained from microorganisms or their metabolic products; are used for active immunization of humans and animals for prophylactic and therapeutic purposes. consist of an active principle - a specific antigen; a preservative to maintain sterility (in non-living V.); a stabilizer, or protector, to increase the shelf life of the antigen; a nonspecific activator (adjuvant), or polymeric carrier, to increase the immunogenicity of the antigen (in chemical, molecular vaccines). Specific, contained in V., in response to administration, cause the development of immunological reactions that ensure the body's resistance to pathogenic microorganisms. The following are used as antigens in V.'s design: live weakened (attenuated); inanimate (inactivated, killed) whole microbial cells or viral particles; complex antigenic structures (protective antigens) extracted from microorganisms; waste products of microorganisms - secondary (for example, molecular protective antigens): antigens obtained by chemical synthesis or biosynthesis using genetic engineering methods.

In accordance with the nature of the specific antigen, V. is divided into living, non-living, and combined (both living and non-living microorganisms and their individual antigens). Live V. is obtained from divergent (natural) strains of microorganisms that have weakened virulence for humans, but contain high-grade antigens (for example, vaccinia), and from artificial (attenuated) strains of microorganisms. Live V. can also include vector V., obtained by a genetically engineered method and representing a vaccine carrying a foreign antigen (for example, a smallpox virus with a built-in antigen of the hepatitis B virus).

Inanimate V. are subdivided into molecular (chemical) and corpuscular. Molecular V. are constructed on the basis of specific protective antigens in a molecular form and obtained by biosynthesis or chemical synthesis. These V. can also include, which are molecules of toxins formed by a microbial cell (diphtheria, tetanus, botulinum, etc.) neutralized by formalin. Corpuscular V. is obtained from whole microorganisms inactivated by physical (heat, ultraviolet and other radiation) or chemical (alcohol) methods (corpuscular, viral, and bacterial vaccines), or from subcellular supra-molecular antigenic structures extracted from microorganisms (subvirion vaccines, split vaccines, vaccines from complex antigenic complexes).

Molecular antigens, or complex protective antigens of bacteria and viruses, are used to obtain synthetic and semi-synthetic vaccines, which are a complex of a specific antigen, a polymer carrier and an adjuvant. Complicated preparations consisting of several monovaccines are prepared from individual V. (monovaccines) intended for immunization against one infection. Such associated vaccines, or polyvaccines, multivalent vaccines provide simultaneously against multiple infections. An example is the associated DPT vaccine, which includes adsorbed diphtheria and tetanus toxoids and corpuscular pertussis. There are also polyanatoxins: botulinum pentaanatoxin, antigangrenous tetraanatoxin, diphtheria-tetanus dianatoxin. For the prevention of poliomyelitis, a single polyvalent one, consisting of attenuated strains of I, II, III serotypes (serovars) of the poliomyelitis virus, is used.

There are about 30 vaccine preparations used to prevent infectious diseases; about half of them are alive, the rest are inactivated. Among living V., bacteria are distinguished — anthrax, plague, tularemia, tuberculosis, and against Q fever; viral - smallpox, measles, influenza, poliomyelitis, mumps, against yellow fever, rubella. Pertussis, dysentery, typhoid, cholera, herpetic, typhus, against tick-borne encephalitis, hemorrhagic fevers, and others, as well as toxoids - diphtheria, tetanus, botulinum, and gas gangrene are used from non-living V.

The main property of V. is the creation of active post-vaccination immunity, which by its nature and final effect corresponds to post-infectious immunity, sometimes differing in it only quantitatively. The vaccination process with the introduction of live V. is reduced to the multiplication and generalization of the attenuated strain in the vaccinated organism and the involvement of the immune system in the process. Although the nature of the post-vaccination reactions with the introduction of live V. the vaccination process resembles an infectious one, it differs from it in its benign course.

Vaccines, when introduced into the body, cause an immune response, which, depending on the nature of immunity and the properties of the antigen, can be pronounced, cellular or cellular-humoral (see Immunity) .

The effectiveness of V.'s use is determined by the immunological reactivity, which depends on the genetic and phenotypic characteristics of the organism, on the quality of the antigen, the dose, the frequency and the interval between inoculations. Therefore, for each V., a vaccination schedule is developed (see.Immunization) . Live V. is usually used once, inanimate - more often twice or three times. Post-vaccination immunity persists after primary vaccination for 6-12 months. (for weak vaccines) and up to 5 years or more (for strong vaccines); supported by periodic revaccinations. (strength) of the vaccine is determined by the protection coefficient (the ratio of the number of diseases among the unvaccinated to the number of cases among the vaccinated), which can vary from 2 to 500. Weak vaccines with a protection coefficient from 2 to 10 include influenza, dysentery, typhoid, etc., to strong with a protection factor from 50 to 500 - smallpox, tularemia, against yellow fever, etc.

Depending on the method of application, V. is divided into injection, oral, and inhalation. In accordance with this, an appropriate dosage form is given: for injections, use the original liquid or rehydrated from a dry state B .; oral V. - in the form of tablets, candies () or capsules; dry (dusty or rehydrated) vaccines are used for inhalation. Century for injection is injected cutaneously (), subcutaneously, intramuscularly.

The easiest to manufacture are live V., since the technology basically boils down to growing an attenuated vaccine strain under conditions that ensure the production of pure cultures of the strain, excluding the possibility of contamination by other microorganisms (mycoplasses, oncoviruses), followed by stabilization and standardization of the final preparation. Vaccine strains of bacteria are grown on liquid nutrient media (casein hydrolysates or other protein-carbohydrate media) in apparatus - fermenters with a capacity of 0.1 m 3 up to 1-2 m 3... The resulting pure culture of the vaccine strain is freeze-dried with the addition of protectors. Viral and rickettsial live V. are obtained by growing the vaccine strain in chicken or quail embryos free of leukemia viruses, or in cell cultures devoid of mycoplasmas. Either primary trypsinized animal cells or transplantable diploid human cells are used. Live attenuated strains of bacteria and viruses used for the preparation of live V. are obtained, as a rule, from natural strains by selection or passage through biological systems (animal organisms, chicken embryos, cell cultures,).

In connection with the advances in genetics and genetic engineering, opportunities have emerged for the purposeful design of vaccine strains. Recombinant strains of the influenza virus, as well as strains of the vaccine virus with built-in genes for protective antigens of the hepatitis B virus have been obtained. live vaccines, and then subjected to inactivation by heating (heated vaccines), formalin (formol vaccines), ultraviolet radiation (UV vaccines), ionizing radiation (radio vaccines), alcohol (alcohol vaccines). Inactivated V. due to insufficiently high immunogenicity and increased reactogenicity have not found widespread use.

The production of molecular vitamins is a more complex technological process, since requires the extraction of protective antigens or antigenic complexes from the grown microbial mass, purification and concentration of antigens, and the introduction of adjuvants into the preparations. and purification of antigens using traditional methods (extraction with trichloroacetic acid, acid or alkaline hydrolysis, enzymatic hydrolysis, salting out with neutral salts, precipitation with alcohol or acetone) are combined using modern methods (high-speed ultracentrifugation, membrane ultrafiltration, chromatographic separation, affinity chromatography, incl. including monoclonal antibodies). With the help of these methods, it is possible to obtain antigens of a high degree of purification and concentration. To the purified antigens, standardized by the number of antigenic units, in order to increase the immunogenicity, adjuvants are added, most often sorbents-gels (aluminum oxide hydrate, etc.). Preparations in which the antigen is in a sorbed state are called sorbed or adsorbed (diphtheria, tetanus, botulinum sorbed toxoids). The sorbent plays the role of a carrier and an adjuvant. All kinds of vaccines have been proposed as a carrier in synthetic vaccines.

A genetically engineered method for obtaining protective protein antigens of bacteria and viruses is being intensively developed. Usually, yeast, pseudomonads with built-in genes of protective antigens are used as producers. Recombinant strains of bacteria producing antigens of pathogens of influenza, whooping cough, measles, herpes, hepatitis B, rabies, foot and mouth disease, HIV infection, etc. , or when it is difficult to extract antigen from a microbial cell. The principle and technology of obtaining V. based on a genetically engineered method are reduced to growing a recombinant strain, isolating and purifying a protective antigen, and designing the final product.

V.'s preparations intended for the immunization of people are tested for harmlessness and immunogenicity. Harmlessness includes testing on laboratory animals and other biological systems for toxicity, pyrogenicity, sterility, allergenicity, teratogenicity, and mutagenicity of V. side local and general reactions to V.'s administration are assessed on animals and during vaccinations of humans. tested in laboratory animals and expressed in immunizing units, i.e. in doses of antigen that protect 50% of immunized animals infected with a certain number of infectious doses of a pathogenic microbe or toxin. In anti-epidemic practice, the effect of vaccination is assessed by the ratio of infectious diseases in vaccinated and unvaccinated groups. V. control is carried out in production in the departments of bacteriological control and in the State Research Institute for Standardization and Control of Medical Biological Products named after V.I. L.A. Tarasovich according to the normative and technical documentation developed and approved by the USSR Ministry of Health.

Vaccine prophylaxis takes an important place in the fight against infectious diseases. Thanks to vaccine prophylaxis, poliomyelitis and diphtheria have been eliminated and minimized, the incidence of measles, whooping cough, anthrax, tularemia and other infectious diseases has been sharply reduced. Vaccine prophylaxis success depends on the quality of vaccines and timely vaccination coverage of threatened contingents. Great tasks are facing the improvement of V. against influenza, rabies, intestinal infections, and others, as well as the development of V. against syphilis, HIV infection, glanders, melioidosis, Legionnaires' disease, and some others. Modern and vaccine prophylaxis have provided a theoretical basis and outlined ways for improving V. in the direction of creating purified polyvalent adjuvant synthetic V. and obtaining new harmless effective live recombinant vaccines.

Bibliography: Burgasov P.N. State and prospects of further decrease in infectious morbidity in the USSR, M., 1987; Vorobiev A.A. and V.A. Lebedinsky. Mass methods of immunization, M., 1977; Gapochko K.G. and others. Vaccines, post-vaccination reactions and the functional state of the vaccinated organism, Ufa, 1986; Zhdanov V.M., Dzagurov S.G. and Saltykov R.A. Vaccines, BME, 3rd ed., Vol. 3, p. 574, M., 1976; N.P. Mertvetsov, A.B. Beklemishev and Savich I.M. Modern approaches to the design of molecular vaccines, Novosibirsk, 1987; R.V. Petrov and Khaitov R.M. Artificial antigens and vaccines, M., 1988, bibliogr.

1. Small medical encyclopedia. - M .: Medical encyclopedia. 1991-96 2. First aid. - M .: Great Russian Encyclopedia. 1994 3. Encyclopedic Dictionary of Medical Terms. - M .: Soviet encyclopedia. - 1982-1984.

See what "Vaccines" are in other dictionaries:

Vaccines- one of the types of medical immunobiological preparations (MIBP), intended for the immunoprophylaxis of infectious diseases. Vaccines containing one component are called monovaccines, as opposed to associated vaccines containing ... ... Dictionary-reference book of terms of normative and technical documentation

Vaccines- drugs or medicinal products administered to humans or animals, designed to stimulate their protective immune response in order to prevent disease ...

Vaccination (inoculation) is the introduction of medical immunobiological preparations into the human body to create specific immunity to infectious diseases.

We suggest taking apart each part of this definition to understand what a vaccine is and how it works.

Part 1. Medical immunobiological preparation

All vaccines are medical immunobiological preparations, because they are introduced under the supervision of a physician and contain pathogens (biological) processed using a special technology, against which it is planned to create immunity (immuno-).

In addition to pathogens or their antigen parts, vaccines sometimes contain special permitted preservatives to maintain the sterility of the vaccine during storage, as well as the minimum acceptable amount of those agents that were used to grow and inactivate microorganisms. For example, trace amounts of yeast cells used in the production of hepatitis B vaccines, or trace amounts of chicken egg protein, which are mainly used in the production of influenza vaccines.

Sterility of drugs is ensured by preservatives recommended by the World Health Organization and international organizations for the control of drug safety. These substances are approved for introduction into the human body.

The complete composition of the vaccines is indicated in the instructions for their use. If a person has an established severe allergic reaction to any of the components of a particular vaccine, then this is usually a contraindication to its administration.

Part 2. Introduction to the body

Various methods are used to inject the vaccine into the body, their choice is determined by the mechanism for the formation of protective immunity, and the method of administration is indicated in the instructions for use.

Click on each of the introduction methods to learn more about it.

Intramuscular route of vaccine administration

The most common route for vaccine administration. A good blood supply to the muscles guarantees both the maximum rate of immunity development and its maximum intensity, since more immune cells have the opportunity to "get acquainted" with the vaccine antigens. The remoteness of the muscles from the skin provides a smaller number of adverse reactions, which, in the case of intramuscular administration, are usually reduced to only some discomfort during active movements in the muscles within 1-2 days after vaccination.

Place of introduction: It is not recommended to inject vaccines into the gluteal region. Firstly, the needles of syringe doses of many vaccines are not long enough to reach the gluteus muscle, while, as is known, in both children and adults, the skin-fat layer can have a significant thickness. If the vaccine is given in the gluteal region, it may be injected subcutaneously. It should also be remembered that any injection into the gluteal region carries a certain risk of damage to the sciatic nerve in people with atypical passage in the muscles.

The preferred site of vaccine administration in children of the first years is the anterior-lateral surface of the thigh in its middle third. This is due to the fact that the muscle mass in this place is significant, despite the fact that the subcutaneous fat layer is less developed than in the gluteal region (especially in children who have not yet walked).

In children over two years of age and adults, the preferred site for vaccine administration is the deltoid muscle (muscle thickening in the upper part of the shoulder, above the head of the humerus), due to the small thickness of the skin and sufficient muscle mass to inject 0.5-1.0 ml of vaccine. drug. In children of the first year of life, this place is usually not used due to insufficient development of muscle mass.

Vaccination technique: Usually, intramuscular injection is performed perpendicularly, that is, at an angle of 90 degrees to the surface of the skin.

Advantages: good absorption of the vaccine and, as a result, high immunogenicity and rate of immunity production. Fewer local adverse reactions.

Flaws: The subjective perception of intramuscular injections in young children is somewhat worse than with other methods of vaccination.

Oral (i.e. by mouth)

The classic example of an oral vaccine is OPV, a live polio vaccine. Usually, live vaccines are administered in this way to protect against intestinal infections (polio, typhoid fever).

Oral vaccination technique: a few drops of the vaccine are put into the mouth. If the vaccine tastes bad, it can be placed either on a sugar cube or on a cookie.

Advantages This route of administration of the vaccine is obvious: there is no injection, the simplicity of the method, its speed.

Disadvantages The disadvantages of oral administration of vaccines can be considered the spill of the vaccine, the inaccuracy of the dosage of the vaccine (part of the drug can be excreted in the feces without having worked).

Intradermal and cutaneous

BCG is a classic example of a vaccine intended for intradermal administration. Live tularemia vaccine and variola vaccine are also examples of intradermal vaccines. As a rule, live bacterial vaccines are injected intradermally, the spread of microbes from which throughout the body is highly undesirable.

Technics: The traditional site for the cutaneous administration of vaccines is either the upper arm (above the deltoid muscle) or the forearm, midway between the wrist and the elbow. For intradermal administration, special syringes with special, thin needles should be used. The needle is inserted upward with a cut, almost parallel to the surface of the skin, pulling the skin up. In doing so, you must make sure that the needle does not penetrate the skin. The correctness of the introduction will be evidenced by the formation of a specific "lemon crust" at the injection site - a whitish skin tone with characteristic depressions at the exit site of the ducts of the cutaneous glands. If the "lemon peel" does not form during the injection, then the vaccine is being administered incorrectly.

Advantages: Low antigenic load, relative painlessness.

Flaws: Quite a complex vaccination technique that requires special training. Possibility to administer the vaccine incorrectly, which can lead to post-vaccination complications.

Subcutaneous route of administration of vaccines

Quite a traditional way of administering vaccines and other immunobiological preparations on the territory of the former USSR, well known to all injections "under the scapula". In general, this route is suitable for live and inactivated vaccines, although it is preferable to use it specifically for live ones (measles-mumps-rubella, yellow fever, etc.).

Due to the fact that subcutaneous administration may slightly decrease immunogenicity and the rate of development of an immune response, this route of administration is extremely undesirable for the administration of vaccines against rabies and viral hepatitis B.

The subcutaneous route of administration of vaccines is desirable for patients with blood coagulation disorders - the risk of bleeding in such patients after subcutaneous injection is much lower than with intramuscular injection.

Technics: The site of vaccination can be both the shoulder (the lateral surface of the middle between the shoulder and elbow joints) and the anterolateral surface of the middle third of the thigh. With the index and thumb, the skin is folded and, at a slight angle, the needle is inserted under the skin. If the patient's subcutaneous layer is significantly pronounced, the formation of a fold is not critical.

Advantages: Comparative simplicity of technique, slightly less pain (which is insignificant in children) compared with intramuscular injection. Unlike intradermal administration, a larger volume of vaccine or other immunobiological preparation can be administered. Accuracy of the administered dose (compared to intradermal and oral administration).

Flaws:"Deposition" of the vaccine and, as a consequence, a lower rate of development of immunity and its intensity with the introduction of inactivated vaccines. A greater number of local reactions - redness and induration at the injection site.

Aerosol, intranasal (i.e. through the nose)

It is believed that this route of vaccine administration improves immunity at the entrance gate of airborne infections (for example, with influenza) by creating an immunological barrier on the mucous membranes. At the same time, the immunity created in this way is not stable, and at the same time, the general (so-called systemic) immunity may be insufficient to fight bacteria and viruses that have already entered the body through the barrier on the mucous membranes.

Aerosol vaccination technique: a few drops of the vaccine are instilled into the nose or sprayed into the nasal passages using a special device.

Advantages such a route of administration of the vaccine is obvious: as with oral vaccination, an injection is not required for aerosol administration; this vaccination creates excellent immunity in the mucous membranes of the upper respiratory tract.

Disadvantages intranasal administration of vaccines can be considered a significant spill of the vaccine, the loss of the vaccine (part of the drug enters the stomach).

Part 3. Specific immunity

Vaccines protect only against those diseases against which they are intended, this is the specificity of immunity. The causative agents of infectious diseases are many: they are divided into different types and subtypes; to protect against many of them, specific vaccines with different possible spectra of protection have already been created or are being created.

For example, modern vaccines against pneumococcus (one of the causative agents of meningitis and pneumonia) can contain 10, 13 or 23 strains. And although scientists know about 100 subtypes of pneumococcus, vaccines include the most common in children and adults, for example, the widest spectrum of protection to date - of 23 serotypes.

However, it must be borne in mind that the vaccinated person is likely to meet some rare subtype of microorganism that is not included in the vaccine and can cause disease, since the vaccine does not form protection against this rare microorganism that is not included in its composition.

Does this mean that the vaccine is not needed, since it cannot protect against all diseases? NO! The vaccine provides good protection against the most common and dangerous ones.

The vaccination calendar will tell you which infections you need to vaccinate. And the mobile application "Baby-Guide" will help you not to forget about the timing of childhood vaccinations.

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Over the centuries, humanity has experienced more than one epidemic that has claimed the lives of many millions of people. Thanks to modern medicine, it has been possible to develop drugs that allow you to avoid many deadly diseases. These drugs are called "vaccines" and are classified into several types, which we will describe in this article.

What is a vaccine and how does it work?

A vaccine is a medical product containing killed or weakened pathogens of various diseases or synthesized proteins of pathogenic microorganisms. They are introduced into the human body to create immunity to a certain disease.

The introduction of vaccines into the human body is called vaccination, or inoculation. The vaccine, entering the body, induces the human immune system to produce special substances to destroy the pathogen, thereby forming in him a selective memory for the disease. Subsequently, if a person becomes infected with this disease, his immune system will quickly counter the pathogen and the person will not get sick at all or suffer a mild form of the disease.

Vaccination methods

Immunobiological drugs can be administered in various ways according to the instructions for vaccines, depending on the type of drug. There are the following methods of vaccination.

The introduction of the vaccine intramuscularly. The place of vaccination in children under one year old is the upper surface of the middle of the thigh, and it is preferable for children from 2 years old and adults to inject the drug into the deltoid muscle, which is located in the upper part of the shoulder. The method is applicable when an inactivated vaccine is needed: DPT, ADS, against viral hepatitis B and influenza vaccine.

Parental feedback suggests that infants tolerate vaccination better in the upper thigh than in the buttock. Physicians adhere to the same opinion, explaining this by the fact that in the gluteal region there may be an abnormal placement of nerves, which is found in 5% of children under one year old. In addition, children of this age have a significant fat layer in the gluteal region, which increases the likelihood of the vaccine entering the subcutaneous layer, which reduces the effectiveness of the drug.

Subcutaneous injections are injected with a thin needle under the skin in the deltoid or forearm. An example is BCG, smallpox vaccination.

The intranasal method is applicable for vaccines in the form of an ointment, cream or spray (measles, rubella vaccination).
The oral route is when a droplet vaccine is placed in the patient's mouth (polio).

Types of vaccines

Today, in the hands of medical workers in the fight against dozens of infectious diseases, there are more than a hundred vaccines, thanks to which it was possible to avoid whole epidemics and significantly improve the quality of medicine. It is conventionally accepted to distinguish 4 types of immunobiological drugs:

Live vaccine (against poliomyelitis, rubella, measles, mumps, influenza, tuberculosis, plague, anthrax).
Inactivated vaccine (against whooping cough, encephalitis, cholera, meningococcal infection, rabies, typhoid fever, hepatitis A).
Toxoids (tetanus and diphtheria vaccines).
Molecular or biosynthetic vaccines (for hepatitis B).

Types of vaccines

Vaccines can also be grouped according to their composition and method of obtaining them:

Corpuscular, that is, consisting of whole microorganisms of the pathogen.
Component or acellular consists of parts of the pathogen, the so-called antigen.
Recombinant: This group of vaccines contains antigens from a pathogenic microorganism that have been genetically engineered into the cells of another microorganism. A representative of this group is the influenza vaccine. Another striking example is the vaccine against viral hepatitis B, which is obtained by introducing an antigen (HBsAg) into yeast cells.

Another criterion by which a vaccine is classified is the number of diseases or pathogens it prevents:

Monovalent vaccines are used to prevent only one disease (for example, the BCG vaccine against tuberculosis).
Polyvalent or associated - for vaccination against several diseases (for example, DPT against diphtheria, tetanus and whooping cough).

Live vaccine

Live vaccine is an indispensable drug for the prevention of many infectious diseases, which is found only in corpuscular form. A characteristic feature of this type of vaccine is that its main component is weakened strains of the infectious agent that can multiply, but are genetically devoid of virulence (the ability to infect the body). They contribute to the body's production of antibodies and immune memory.

The advantage of live vaccines is that the pathogens that are still live, but weakened, induce the human body to develop long-term immunity (immunity) to this pathogenic agent, even with a single vaccination. There are several ways to administer the vaccine: intramuscularly, under the skin, and nasal drops.

The disadvantage is that a gene mutation of pathogenic agents is possible, which will lead to the disease of the vaccinated. In this regard, it is contraindicated for patients with especially weakened immunity, namely for people with immunodeficiency and cancer patients. Requires special conditions for transportation and storage of the drug in order to ensure the safety of living microorganisms in it.

Inactivated vaccines

The use of vaccines with inactivated (dead) pathogenic agents is widespread for the prevention of viral diseases. The principle of action is based on the introduction into the human body of artificially cultivated and devoid of viability viral pathogens.

In terms of composition, “killed” vaccines can be either whole-microbial (whole-viral) or subunit (component) and genetically engineered (recombinant).

An important advantage of "killed" vaccines is their absolute safety, that is, the absence of the likelihood of infection of the vaccinated person and the development of infection.

The disadvantage is a lower duration of immune memory compared to "live" vaccinations, inactivated vaccines also retain the likelihood of developing autoimmune and toxic complications, and to form a full-fledged immunization, several vaccination procedures are required with maintaining the required interval between them.

Toxoid

Toxoids are vaccines created on the basis of disinfected toxins released during the life of some pathogens of infectious diseases. The peculiarity of this vaccination is that it provokes the formation of not microbial immunity, but antitoxic immunity. Thus, toxoids are successfully used for the prevention of those diseases in which clinical symptoms are associated with a toxic effect (intoxication) resulting from the biological activity of a pathogenic pathogen.

Release form - transparent liquid with sediment in glass ampoules. Before use, you need to shake the contents to evenly distribute the toxoid.

The advantages of toxoids are indispensable for the prevention of those diseases against which live vaccines are powerless, moreover, they are more resistant to temperature fluctuations, do not require special storage conditions.

Disadvantages of toxoids - they induce only antitoxic immunity, which does not exclude the possibility of the occurrence of localized diseases in the vaccinated person, as well as the carriage of pathogens of this disease by him.

Making live vaccines

Mass production of the vaccine began at the beginning of the 20th century, when biologists learned how to weaken viruses and pathogenic microorganisms. Live vaccine is about half of all prophylactic drugs used in world medicine.

The production of live vaccines is based on the principle of reseeding the pathogen into an organism that is immune or slightly susceptible to this microorganism (virus), or the cultivation of the pathogen in unfavorable conditions for it with the effect of physical, chemical and biological factors on it, followed by selection of non-virulent strains. Most often, the substrate for the cultivation of avirulent strains is chicken embryos, primary cellular (chicken or quail ebryonic fibroblasts) and transplanted cultures.

Getting "killed" vaccines

The production of inactivated vaccines differs from live ones in that they are obtained by killing, and not by attenuating, the pathogen. For this, only those pathogenic microorganisms and viruses that have the highest virulence are selected; they must be of the same population with clearly delineated characteristic features for it: shape, pigmentation, size, etc.

Inactivation of the pathogen colonies is carried out in several ways:

overheating, that is, exposure of the cultivated microorganism to an elevated temperature (56-60 degrees) for a certain time (from 12 minutes to 2 hours);
exposure to formalin for 28-30 days with maintaining the temperature at 40 degrees, a solution of beta-propiolactone, alcohol, acetone, chloroform can also act as an inactivating chemical reagent.

Making toxoid

In order to obtain a toxoid, toxogenic microorganisms are first cultivated in a nutrient medium, most often of a liquid consistency. This is done in order to accumulate as much exotoxin as possible in the culture. The next stage is the separation of exotoxin from the producer cell and its neutralization using the same chemical reactions that are used for “killed” vaccines: exposure to chemicals and overheating.

To reduce reactivity and susceptibility, antigens are cleared of ballast, concentrated and adsorbed with aluminum oxide. The process of adsorption of antigens plays an important role, since the injected injection with a high concentration of toxoids forms a depot of antigens, as a result, antigens enter and spread throughout the body slowly, thereby ensuring an effective immunization process.

Destruction of unused vaccine

Regardless of which vaccines were used for vaccination, containers with drug residues must be treated in one of the following ways:

boiling used containers and instruments for an hour;
disinfection in a solution of 3-5% chloramine for 60 minutes;
treatment with 6% hydrogen peroxide also for 1 hour.

Expired drugs must be sent to the regional sanitary and epidemiological center for disposal.

1 . By appointment vaccines are divided into preventive and curative.

By the nature of the microorganisms from which they are created,there are wakin:

Bacterial;

Viral;

Rickettsial.

Exists mono- and polyvaccines - prepared respectively from one or more pathogens.

By cooking methoddistinguish between vaccines:

Combined.

To increase immunogenicity to vaccines sometimes they add various kinds adjuvants(potassium alum, aluminum hydroxide or phosphate, oil emulsion), which create a depot of antigens or stimulate phagocytosis and thus increase the foreignness of the antigen to the recipient.

2. Live vaccines contain live attenuated strains of pathogens with sharply reduced virulence or strains of microorganisms, non-pathogenic for humans, closely related to the pathogen in antigenic terms (divergent strains). These include and recombinant(genetically engineered) vaccines containing vector strains of non-pathogenic bacteria / viruses (genes responsible for the synthesis of protective antigens of certain pathogens are introduced into them by genetic engineering methods).

Examples of genetically engineered vaccines are the hepatitis B vaccine - Engerix B and the measles rubella vaccine - Re-combivax HB.

Insofar as live vaccines contain strains of pathogenic microorganisms with a sharply reduced virulence, then, in essence, they reproduce an easy-going infection in the human body, but not an infectious disease, during which the same defense mechanisms are formed and activated as during the development of post-infectious immunity. In this regard, live vaccines, as a rule, create a fairly intense and long-term immunity.

On the other hand, for the same reason, the use of live vaccines against the background of immunodeficiency states (especially in children) can cause severe infectious complications.

For example, a disease defined by clinicians as BCG after administration of the BCG vaccine.

Live vaccines are used for prophylaxis:

Tuberculosis;

Especially dangerous infections (plague, anthrax, tularemia, brucellosis);

Flu, measles, rabies (rabies);

Mumps, smallpox, polio (Seibin-Smorodintsev-Chumakov vaccine);

Yellow fever, measles rubella;

Q fever.

3. Killed vaccines contain killed cultures of pathogens(whole cell, whole virion). They are prepared from microorganisms inactivated by heating (heated), ultraviolet rays, chemicals (formalin - formol, phenol - carbolic, alcohol - alcohol, etc.) under conditions that exclude denaturation of antigens. The immunogenicity of killed vaccines is lower than that of live vaccines. Therefore, the immunity they cause is short-term and relatively less intense. Killed vaccines are used for prophylaxis:

Pertussis, leptospirosis,

Typhoid fever, paratyphoid fever A and B,

Cholera, tick-borne encephalitis,

Poliomyelitis (Salk vaccine), hepatitis A.

TO killed vaccines include and chemical vaccines, containing certain chemical components of pathogens that are immunogenic (subcellular, subvirionic). Since they contain only individual components of bacterial cells or virions that are directly immunogenic, chemical vaccines are less reactogenic and can be used even in preschool children. Also known anti-idiotypic vaccines, which are also referred to as killed vaccines. These are antibodies to one or another idiotype of human antibodies (anti-antibodies). Their active center is analogous to the determinant group of the antigen that caused the formation of the corresponding idiotype.

4. Combined vaccines include artificial vaccines.

They are drugs consisting of microbial antigenic component(usually isolated and purified or artificially synthesized antigen of the pathogen) and synthetic polyions(polyacrylic acid, etc.) - powerful stimulants of the immune response. By the content of these substances, they differ from the chemical killed vaccines. The first such domestic vaccine - influenza polymer-subunit ("Grippol"), developed at the Institute of Immunology, has already been introduced into the practice of Russian health care. For specific prophylaxis of infectious diseases, the causative agents of which produce exotoxin, toxoid is used.

Toxoid - it is an exotoxin devoid of toxic properties, but retaining antigenic properties. Unlike vaccines, when used in humans, antimicrobial immunity, with the introduction of toxoids is formed antitoxic immunity, as they induce the synthesis of antitoxic antibodies - antitoxins.

Currently applied:

Diphtheria;

Tetanus;

Botulinum;

Staphylococcal toxoid;

Cholerogen-toxoid.

Examples of associated vaccinesare:

- DPT vaccine(adsorbed diphtheria-tetanus-pertussis vaccine), in which the pertussis component is the killed pertussis vaccine, and the diphtheria and tetanus-related toxoids;

- vaccine TAVTe, containing O-antigens of typhoid, paratyphoid A- and B-bacteria and tetanus toxoid; typhoid chemical vaccine with sextanatoxin (a mixture of clostridium botulism toxoids of types A, B, E, tetanus clostridia, clostridium perfringens type A and edematiens - the last two microorganisms - the most common causative agents of gas gangrene), etc.

At the same time, ADS (diphtheria-tetanus toxoid), often used instead of DPT when vaccinating children, is just a combination drug, and not an associated vaccine, since it contains only toxoid.

The drug that is vaccinated is called a vaccine. The vaccine contains the main substance - antigen, on which the body of the vaccinated person produces antibodies or forms cells designed to recognize foreign inside other cells and destroy it.

Vaccine preparations are obtained from bacteria, viruses or their metabolic products.

Depending on what is the main active principle of the vaccine (antigen), they release non-living vaccines (inactivated) and live.

Alive are called vaccines that contain live, weakened pathogens. The virus in them is significantly weakened (attenuated), so it cannot cause the corresponding disease (for example, measles). During vaccine production, viruses are weakened until they lose their ability to cause disease, but still retain their ability to form defenses. Live vaccines can contain a microbe as an antigen that does not cause human disease, but creates immunity to pathogens in humans. These are, for example, vaccines against smallpox and tuberculosis.

Inactivated vaccines are obtained in different ways. They can contain a completely killed microorganism - a bacterium or a virus. Such vaccines are called whole-cell or whole-virus vaccines. An example of a whole cell killed vaccine is the pertussis vaccine as part of the combination diphtheria and tetanus vaccine (DPT). Whole virion vaccines are vaccines against hepatitis A, tick-borne encephalitis, and some influenza vaccines.

Non-living vaccines also include subunit and split vaccines, in which the killed virus is cut into small pieces and some of them removed. Most influenza vaccines are split or subunit (Figure 1).

There are chemical vaccines that use separate parts of the microbes or viruses that are responsible for the production of immunity. An example is toxoid. Microbes such as diphtheria and tetanus bacillus secrete toxins that cause illness. Toxins devoid of toxicity are called toxoids and are used as a vaccine. One of the types of chemical vaccines are polysaccharides containing polysaccharides from the cell wall of microbes. Polysaccharide vaccines are used against Haemophilus influenzae type B, pneumococci, and meningococci.

Non-living also include recombinant vaccines that are genetically engineered. The latest vaccines are the safest.

In recent years, there have been many statements that genetically engineered recombinant vaccines affect the human genotype, that these are “embedded chips” that zombify a person. It is difficult to imagine a more absurd statement.

How is a recombinant vaccine made?

The virus that causes the infection consists of an envelope and an internal DNA or RNA molecule. This molecule contains a region (gene) that is responsible for the synthesis of part (molecules) of the virus envelope. Scientists have learned to isolate the RNA or DNA gene responsible for the synthesis of a specific virus envelope molecule. This gene is sewn into nutritional yeast, which we constantly eat, and a region is synthesized on the surface of the yeast that is similar in structure to a region of the virus envelope. This section of yeast is excised and a vaccine is made from it.

It turns out that the recombinant vaccine is a piece of yeast envelope, similar to the envelope of the virus. If they are introduced into the human body, then his immune system synthesizes antibodies to these pieces of yeast, which will protect us from a similar shell of the virus, i.e. from a specific viral infection. Consequently, the recombinant vaccine does not contain the causative agent of infection at all, does not contain either viral or yeast genes, and cannot be incorporated into the genetic apparatus of a human cell.

So it turns out that, despite the name genetically engineered, recombinant, which scares people, these are the safest vaccines today. These include the hepatitis B vaccine, the human papillomavirus vaccine.

There are vaccines directed against one disease (monovaccines), as well as combination vaccines, which are used to vaccinate against several infections at once.