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Currently, mankind knows such types of vaccines that help prevent the development of dangerous infectious diseases and other pathologies. The injection can help the immune system build resistance to certain types of diseases.

Subgroups of vaccines

There are 2 types of vaccinations:

• alive
• inactivated.

Live - in their composition have a mixture of strains of various weakened microorganisms. Loss of pathogenic properties is fixed for vaccine strains. Their action begins in the place where the drug was introduced. When vaccinated by this method, strong immunity is created, which is able to maintain its properties for a long time. Immunotherapy with live microorganisms is used against the following diseases:

• pigs
• rubella
• tuberculosis
• poliomyelitis.

There are a number of disadvantages of living complexes:

1. Difficult to dose and combine.
2. With immunodeficiency can not be used categorically.
3. Unstable.
4. The effectiveness of the drug is reduced due to the naturally circulating virus.
5. During storage and transportation, safety measures must be observed.

Inactivated - or killed. They are specially grown using inactivation. As a result, damage to structural proteins is minimal. Therefore, treatment with alcohol, phenol or formalin is used. At a temperature of 56 degrees for 2 hours, the process of inactivation takes place. Killed vaccines have a shorter duration of action than live vaccines.

Advantages:

• well give in to a dosage and a combination;
• vaccine-associated diseases do not occur;
• they are allowed to be used even with human immunodeficiency.

Flaws:

• a huge number of "ballast" components and others that are not able to participate in the creation of the body's defense;
• allergic or toxic effects may occur.

There is a classification of inactivated drugs. Biosynthetic - the second name is recombinant. They include products of genetic engineering. Often used in combination with other drugs to strengthen the immune system against several diseases at once. Considered safe and effective. The most common injection is for hepatitis B.

Chemical - receive antigens from the cell of the microbe. Use only those cells that can affect the immune system. Polysaccharide and whooping cough injections - they are chemical.

Corpuscular are bacteria or viruses that have been inactivated with formalin, alcohol, or exposure to heat. DPT and tetracoccus vaccination, injection against hepatitis A, influenza belong to this group.

All inactivated drugs can be produced in 2 states: liquid and dry.

The classification of vaccine complexes also follows a different principle. They are distinguished depending on the number of antigens, that is, mono- and polyvaccines. Depending on the composition of the species, they are divided into:

• viral
• bacterial
• rickettsial.

Now they are developing at an accelerated pace:

• synthetic
• anti-idiotypic
• recombinant.

Anatoxins are produced from neutralized exotoxins. Usually aluminum hydroxide is used to sorb toxoids. As a result, antibodies appear in the body that act against toxoids. As a result, their action does not exclude the penetration of bacteria. Toxoids are used against diphtheria and tetanus. 5 years is the maximum term.

DTP - diphtheria, whooping cough, tetanus

The characteristic of this injection is that it acts as a barrier to severe infections. The composition of the drug includes antigens that are able to form bodies that prevent the penetration of infection.

Varieties of the DTP vaccine

DPT - adsorbed pertussis, diphtheria and tetanus vaccination. The injection helps protect a person from the most dangerous diseases. Begin to vaccinate at a very young age. The body of babies can not cope with the disease on their own, so they need to be protected. The first injection is given at 2 or 3 months. When vaccinated with DTP, the reaction may be different, which is why some parents are wary of doing it. Komarovsky: "The risk of complications after vaccination is much lower than in the event of complications from an emerging disease."

There are several certified immunotherapy options. World Organization health care permits all these varieties. The classification of DTP is as follows:

1. Whole cell vaccine - used for children who do not suffer from serious diseases. The composition contains a whole cell of the microbe, which is capable of showing a strong reaction to the body.
2. Acellular - a weakened form. Used for babies if they are not allowed to use the full form. This category includes children who have already had whooping cough, children school age. In this case, there is no pertussis antigen in the injection. After vaccination, complications almost never occur.

Also, manufacturers now offer different forms of DTP. Their characteristic suggests that you can safely use any. What drugs are offered by manufacturers?

1. liquid form. Usually produced by a Russian manufacturer. For the first time, a child is vaccinated at 3 months. Subsequent vaccination is done after 1.5 months.
2. Infanrix. It has the advantage that it can be used in combination with other vaccines.
3. IPV. It's the DTP vaccine against polio.
4. Infanrix hexa. The composition includes components that help fight diphtheria, whooping cough, tetanus, hepatitis B, polio and Haemophilus influenzae.
5. Pentax. Vaccination along with polio and Haemophilus influenzae. French vaccine.
6. Tetracoccus. Also French suspension. Used to prevent DTP and polio.

Dr. Komarovsky: “I consider Pentaxim to be the safest and most effective vaccine, capable of giving a good response to the disease.”

.

Vaccination

Several types of vaccinations may be offered by different clinics. In this case, there are several methods of introduction. You can choose any. Ways:

• intradermal
• subcutaneous
• intranasal
• enteral
• dermal
• combined
• inhalation.

Subcutaneous, intradermal and cutaneous are considered the most painful. When vaccinated in such ways, the integrity of the skin is destroyed. Often these methods are painful. To reduce soreness, a needleless method is used. Under pressure, the jet is injected into the skin or deep into the cells. Using this method, sterility is observed many times higher than with other methods.

Methods that involve not affecting the skin are very fond of children. For example, the polio vaccine is available as a pill. When vaccinating against influenza, the intranasal method is used. But in this case, it is important to prevent leakage of the drug.

Inhalations are the most effective method. Helps to instill a large number of people in a short time. This method of vaccination is not yet so common, but may soon be used everywhere.

vaccine requirements.

Safety is the most important property of a vaccine and is carefully researched and controlled in

production and use of vaccines. A vaccine is safe if given to humans

does not cause the development of serious complications and diseases;

Protectiveness - the ability to induce a specific defense of the body against

certain infectious disease;

Duration of preservation of protectiveness;

Stimulation of the formation of neutralizing antibodies;

Stimulation of effector T-lymphocytes;

Duration of preservation of immunological memory;

Low cost;

Biological stability during transportation and storage;

Low reactogenicity;

Ease of introduction.

Types of vaccines:

Live vaccines are produced on the basis of attenuated strains of a microorganism with genetically fixed avirulence. The vaccine strain, after administration, multiplies in the body of the vaccinated person and causes a vaccinal infectious process. In the majority of those vaccinated, the vaccine infection proceeds without pronounced clinical symptoms and leads to the formation, as a rule, of stable immunity. Examples of live vaccines are vaccines for the prevention of poliomyelitis (Sabin live vaccine), tuberculosis (BCG), mumps, plague, anthrax, tularemia. Live vaccines are available in lyophilized (powdered)

form (except for poliomyelitis). Killed vaccines are bacteria or viruses inactivated by chemical (formalin, alcohol, phenol) or physical (heat, ultraviolet radiation) exposure. Examples of inactivated vaccines are: pertussis (as a component of DTP), leptospirosis, influenza whole virus vaccine, tick-borne encephalitis vaccine, and inactivated polio vaccine (Salk vaccine).

Chemical vaccines are obtained by mechanical or chemical destruction of microorganisms and the isolation of protective, i.e., causing the formation of protective immune responses, antigens. For example, typhoid fever vaccine, meningococcal vaccine.

Anatoxins. These drugs are bacterial toxins rendered harmless

exposure to formalin at elevated temperature (400) for 30 days, followed by purification and concentration. Anatoxins are sorbed on various mineral adsorbents, such as aluminum hydroxide (adjuvants). Adsorption significantly increases the immunogenic activity of toxoids. This is due both to the creation of a "depot" of the drug at the injection site, and to adjuvant

by the action of a sorbent that causes local inflammation, an increase in the plasmacytic reaction in the regional lymph nodes. Anatoxins are used to prevent tetanus, diphtheria, and staphylococcal infections.

Synthetic vaccines are artificially created antigenic determinants of microorganisms.

Associated vaccines include drugs from the previous groups and against several infections. Example: DPT - consists of diphtheria and tetanus toxoid adsorbed on aluminum hydroxide and killed pertussis vaccine.

Vaccines obtained by genetic engineering. The essence of the method: the genes of a virulent microorganism responsible for the synthesis of protective antigens are inserted into the genome of a harmless microorganism, which, when cultivated, produces and accumulates the corresponding antigen. An example is the recombinant hepatitis B vaccine, the rotavirus vaccine.

In the future, it is planned to use vectors in which not only genes are embedded,

controlling the synthesis of pathogen antigens, but also genes encoding various mediators (proteins) of the immune response (interferons, interleukins, etc.

Currently, vaccines are being intensively developed from plasmid (extranuclear) DNA encoding antigens of pathogens of infectious diseases. The idea of ​​such vaccines is to insert the microorganism's genes responsible for microbial protein synthesis into the human genome. At the same time, human cells stop producing this protein that is foreign to them, and the immune system will begin to produce antibodies to it. These antibodies will neutralize the pathogen if it enters the body.

71Vaccination immunity. Factors affecting its development Methods of determination

tension of post-vaccination immunity. The value of herd immunity, methods of its assessment.

Post-vaccination immunity - immunity that develops after the introduction of a vaccine. For the development of post-vaccination immune system<эдду»ОЩ)Кф|КТОры: Dependent on the vaccine itself

The quality of the drug

Presence of protective antigens

Multiplicity of introduction

dependent on the body

individual immune status resilience; age,

the presence of immunodeficiency, the state of the body as a whole depends on the external environment, nutrition,

working and living conditions, flora and fauna,

physical and chemical environmental factors

Methods for monitoring the effectiveness of post-vaccination immunity

To assess the state of artificial post-vaccination immunity, the following methods are used

Statement of serological reactions with sera of vaccinated, skin immunological tests, skin-allergic tests

The assessment of the state of immunity in the population is carried out mainly to infections controlled by means of specific prophylaxis - whooping cough, measles, paratitis, diphtheria and tetanus. Effective vaccines are available against these infections. In addition, they selectively monitor the effectiveness of immunoprophylaxis and the state of collective immunity to influenza, poliomyelitis, tuberculosis, tularemia, brucellosis and other infections

To monitor the state of immunity, highly specific and, at the same time, harmless methods are used that are available for mass examination. finger 1.5 ml - 0.75 ml of serum Each sample of serum is examined for the presence of antibodies to various pathogens Indicators for assessing immunological protection are antibody titers to diphtheria and tetanus 1 20 to measles -1 4

To detect immunity to whooping cough, RA is put, a protective antibody titer of 1 100 Data on seronegative individuals who do not have a protective antibody titer are transferred to the clinic for the development of individual immunization schemes

The state of immunity to influenza viruses is also constantly monitored. antibodies 1 16 - strained immunity To control immunity to diphtheria in children's groups (according to epidemiological indicators or dubious quality of vaccinations), the Schick immunological test is also used - intradermal administration of a minimum dose of diluted diphtheria toxin If there is a sufficient titer of antibodies (antitoxin) in the blood, the injected toxin is neutralized and there is no skin reaction. The effectiveness of tularemia vaccine prevention is also monitored by setting up a skin-allergic test for tularin; if the test is negative, there is no immunity. staging a skin-allergic test to monitor the state of immunity to tetanus Immunological monitoring of the effectiveness of vaccination allows assessing the actual protection against this infection and the quality of vaccination work and, if necessary,

72. Passive immunoprophylaxis - the creation of immunity by the introduction of serum preparations and

gamma globulin;

Serum preparations - contain ready-made antibodies. Depending on the purpose, they are divided into

treatment-and-prophylactic and diagnostic, from the degree of purification - to serum,

polyglobulin and gamma globulin preparations, originated from animals and

human; the latter are divided into donor and placental.

Three methods are currently used for the manufacture of serum preparations:

1. Immunization of animals in order to obtain polyvalent sera, i.e. containing antibodies to both specific and group antigens of the immunizing microbe. Such serums often give the so-called. group serological reactions. Therefore, in order to increase their specificity, antibodies to group antigens are adsorbed from them:

2. Obtaining monoclonal antibodies produced after immunization of the animal by individual plasma cells "fused" with cells of certain tumor lines. Such a hybridoma has a united genome: from a plasma cell it inherits the ability to produce certain antibodies, from a tumor cell it inherits the ability for long-term reproduction. The purpose of hybridomas is the long-term production of antibodies of one specificity.

3. Obtaining the serum of people who have previously been ill or vaccinated and therefore have certain antibody titers, as a rule, to pathogens of various infectious diseases. Serum is obtained either from donors or from a mixture of placental blood. They usually contain antibodies to the measles virus, and in different amounts of antibodies to staphylococci, streptococci, Escherichia, Proteus, Pseudomonas, influenza, whooping cough, polio, infectious hepatitis.

Therapeutic and prophylactic serum preparations are used to create an artificial

passive immunity in emergency prevention and immunotherapy of the following diseases:

staphylococcal infections - anti-staphylococcal human plasma or anti-staphylococcal

human immunoglobulin;

whooping cough - normal human immunoglobulin;

influenza - donor gamma globulin;

measles - normal human immunoglobulin;

poliomyelitis - normal human immunoglobulin;

hepatitis A - normal human immunoglobulin;

tetanus - antitoxic horse serum or (in persons allergic to horse protein) -

protetanus antitoxic human immunoglobulin (from vaccinated donors);

wound anaerobic infections - antigangrenous (antiperfringens A, antiedematieno,

antiseptic) horse serum;

botulism - antibotulinum A, B, C. horse sera;

diphtheria - antitoxic horse serum;

rabies - anti-rabies equine gamma globulin and immunoglobulin from human serum,

vaccinated against rabies

73 Herd immunity - population immunity

Defined:

The number of recoveries

The number of people vaccinated against this infection

Immune layer number of individuals (%) in the population,

immune to this disease.

The higher this indicator, the higher

herd immunity level.

Matters for:

Forecasting the epidemiological process

Immunization planning

Evaluation of the quality of immunoprophylaxis

74.ALLERGY (from the Greek allos - another) - a form of immune response, specific hypersensitivity of the body to the allergen (antigen) as a result of an inadequate response of the immune system to repeated contact with the allergen, which leads to tissue damage.

Today's article opens the heading "Vaccination" and it will talk about what are types of vaccines and how they differ, how they are obtained and in what ways they are introduced into the body.

And it would be logical to start with the definition of what a vaccine is. So, vaccine- This is a biological preparation designed to create a specific immunity of the body to a specific causative agent of an infectious disease by developing active immunity.

Under vaccination (immunization), in turn, refers to the process during which the body acquires active immunity to an infectious disease through the introduction of a vaccine.

Types of vaccines

The vaccine may contain live or killed microorganisms, parts of microorganisms responsible for the development of immunity (antigens) or their neutralized toxins.

If the vaccine contains only individual components of the microorganism (antigens), then it is called component (subunit, acellular, acellular).

According to the number of pathogens against which they are conceived, vaccines are divided into:

• monovalent (simple)- against one pathogen
• polyvalent- against several strains of the same pathogen (for example, the polio vaccine is trivalent, and the Pneumo-23 vaccine contains 23 pneumococcal serotypes)
• associated (combined)- against several pathogens (DPT, measles - mumps - rubella).

Consider the types of vaccines in more detail.

Live attenuated vaccines

Live attenuated (attenuated) vaccines obtained from artificially modified pathogenic microorganisms. Such weakened microorganisms retain the ability to multiply in the human body and stimulate the production of immunity, but do not cause disease (that is, they are avirulent).

Attenuated viruses and bacteria are usually obtained by repeated cultivation in chick embryos or cell cultures. This is a lengthy process that can take up to 10 years.

A variety of live vaccines are divergent vaccines, in the manufacture of which microorganisms are used that are closely related to the causative agents of human infectious diseases, but are not capable of causing a disease in him. An example of such a vaccine is BCG, which is obtained from Mycobacterium bovine tuberculosis.

All live vaccines contain whole bacteria and viruses, therefore they are classified as corpuscular.

The main advantage of live vaccines is the ability to induce persistent and long-term (often lifelong) immunity after a single injection (except for those vaccines that are administered by mouth). This is due to the fact that the formation of immunity to live vaccines is closest to that in the natural course of the disease.

When using live vaccines, there is a possibility that, multiplying in the body, the vaccine strain can return to its original pathogenic form and cause a disease with all clinical manifestations and complications.

Such cases are known for live polio vaccine (OPV), so in some countries (USA) it is not used.

Live vaccines should not be administered to people with immunodeficiency diseases (leukemia, HIV, treatment with drugs that cause suppression of the immune system).

Other disadvantages of live vaccines are their instability even with minor violations of storage conditions (heat and light are detrimental to them), as well as inactivation, which occurs when antibodies to this disease are present in the body (for example, when antibodies to a given disease are still circulating in a child’s blood, received through the placenta from the mother).

Examples of live vaccines: BCG, vaccines against measles, rubella, chickenpox, mumps, polio, influenza.

Inactivated vaccines

Inactivated (killed, non-live) vaccines, as the name suggests, do not contain living microorganisms, therefore cannot cause disease even theoretically, including those with immunodeficiency.

The effectiveness of inactivated vaccines, unlike live ones, does not depend on the presence of circulating antibodies to this pathogen in the blood.

Inactivated vaccines always require multiple vaccinations. A protective immune response usually develops only after the second or third dose. The number of antibodies gradually decreases, therefore, after some time, re-vaccination (revaccination) is required to maintain the antibody titer.

In order for immunity to form better, special substances are often added to inactivated vaccines - adsorbents (adjuvants). Adjuvants stimulate the development of an immune response, causing a local inflammatory reaction and creating a depot of the drug at the injection site.

Insoluble aluminum salts (aluminum hydroxide or aluminum phosphate) usually act as adjuvants. In some Russian-made influenza vaccines, polyoxidonium is used for this purpose.

These vaccines are called adsorbed (adjuvant).

Inactivated vaccines, depending on the method of preparation and the condition of the microorganisms they contain, can be:

• Corpuscular- contain whole microorganisms killed by physical (heat, ultraviolet radiation) and / or chemical (formalin, acetone, alcohol, phenol) methods.
  These vaccines are: pertussis component of DTP, vaccines against hepatitis A, polio, influenza, typhoid, cholera, plague.
• Subunit (component, acellular) vaccines contain separate parts of the microorganism - antigens that are responsible for the development of immunity to this pathogen. Antigens can be proteins or polysaccharides that are isolated from a microbial cell using physicochemical methods. Therefore, such vaccines are also called chemical.
  Subunit vaccines are less reactogenic than corpuscular ones, because everything superfluous has been removed from them.
  Examples of chemical vaccines: polysaccharide pneumococcal, meningococcal, hemophilic, typhoid; pertussis and influenza vaccines.
• Genetically engineered (recombinant) vaccines are a type of subunit vaccines, they are obtained by embedding the genetic material of a microbe - the causative agent of the disease into the genome of other microorganisms (for example, yeast cells), which are then cultivated and the desired antigen is isolated from the resulting culture.
  Examples are vaccines against hepatitis B and human papillomavirus.
• Two more types of vaccines are in the stage of experimental studies - these are DNA vaccines And recombinant vector vaccines. It is expected that both types of vaccines will provide protection at the level of live vaccines, while being the safest.
  DNA vaccines against influenza and herpes and vector vaccines against rabies, measles and HIV infection are currently being studied.

Toxoid vaccines

In the mechanism of development of some diseases, the main role is played not by the pathogen itself, but by the toxins that it produces. One example of such a disease is tetanus. The causative agent of tetanus produces a neurotoxin called tetanospasmin, which causes symptoms.

To create immunity to such diseases, vaccines are used that contain neutralized toxins of microorganisms - toxoids (toxoids).

Anatoxins are obtained using the physicochemical methods described above (formalin, heat), then they are purified, concentrated and adsorbed on an adjuvant to enhance the immunogenic properties.

Toxoids can be conditionally attributed to inactivated vaccines.

Examples of toxoid vaccines: tetanus and diphtheria toxoids.

conjugate vaccines

These are inactivated vaccines, which are a combination of bacterial parts (purified cell wall polysaccharides) with carrier proteins, which are bacterial toxins (diphtheria toxoid, tetanus toxoid).

In this combination, the immunogenicity of the polysaccharide fraction of the vaccine is significantly enhanced, which by itself cannot cause a full-fledged immune response (in particular, in children under 2 years of age).

Currently, conjugate vaccines against Haemophilus influenzae and pneumococcus have been developed and are being used.

Ways of administering vaccines

Vaccines can be administered by almost all known methods - through the mouth (orally), through the nose (intranasal, aerosol), skin and intradermal, subcutaneous and intramuscular. The method of administration is determined by the properties of a particular drug.

Skin and intradermal mainly live vaccines are introduced, the distribution of which throughout the body is highly undesirable due to possible post-vaccination reactions. In this way, BCG, vaccines against tularemia, brucellosis and smallpox are introduced.

oral only those vaccines can be administered, the pathogens of which use the gastrointestinal tract as an entrance gate into the body. The classic example is the live polio vaccine (OPV), live rotavirus and typhoid vaccines are also administered. Within an hour after vaccination, Russian-made AFP should not be drunk or eaten. This restriction does not apply to other oral vaccines.

intranasally a live influenza vaccine is given. The purpose of this method of administration is to create immunological protection in the mucous membranes of the upper respiratory tract, which are the entrance gates for influenza infection. At the same time, systemic immunity with this route of administration may be insufficient.

subcutaneous method suitable for the introduction of both live and inactivated vaccines, but has a number of disadvantages (in particular, a relatively large number of local complications). It is advisable to use it in people with a bleeding disorder, since in this case the risk of bleeding is minimal.

Intramuscular administration vaccines is optimal, because on the one hand, due to good blood supply to the muscles, immunity is developed quickly, on the other hand, the likelihood of local adverse reactions is reduced.

In children under two years of age, the preferred site for administering the vaccine is the middle third of the anterior-lateral surface of the thigh, and in children after two years of age and adults, the deltoid muscle (upper outer third of the shoulder). This choice is explained by a significant muscle mass in these places and a less pronounced subcutaneous fat layer than in the gluteal region.

That's all, I hope that I was able to present a rather difficult material about what are types of vaccines, in an easy-to-understand form.

They are a suspension of vaccine strains of microorganisms (bacteria, viruses, rickettsia) grown on various nutrient media. Usually, strains of microorganisms with weakened virulence or devoid of virulence properties, but completely retained immunogenic properties, are used for vaccination. These vaccines are produced on the basis of apathogenic pathogens, attenuated (weakened) in artificial or natural conditions. Attenuated strains of viruses and bacteria are obtained by inactivation of the gene responsible for the formation of the virulence factor, or by mutations in genes that nonspecifically reduce this virulence.

In recent years, recombinant DNA technology has been used to obtain attenuated strains of some viruses. Large DNA-containing viruses, such as the vaccinia virus, can serve as vectors for cloning foreign genes. Such viruses retain their infectivity, and the cells infected by them begin to secrete proteins encoded by the transfected genes.

Due to the genetically fixed loss of pathogenic properties and the loss of the ability to cause an infectious disease, vaccine strains retain the ability to multiply at the injection site, and later in the regional lymph nodes and internal organs. Vaccine infection lasts for several weeks, is not accompanied by a pronounced clinical picture of the disease and leads to the formation of immunity to pathogenic strains of microorganisms.

Live attenuated vaccines are prepared from attenuated microorganisms. Weakening of microorganisms is also achieved by growing crops in adverse conditions. Many vaccines are produced in dry form in order to increase the shelf life.

Live vaccines have significant advantages over killed ones, due to the fact that they completely preserve the antigenic set of the pathogen and provide a longer state of immunity. However, given the fact that the active principle of live vaccines are live microorganisms, it is necessary to strictly comply with the requirements that ensure the preservation of the viability of microorganisms and the specific activity of vaccines.

There are no preservatives in live vaccines; when working with them, it is necessary to strictly observe the rules of asepsis and antisepsis.

Live vaccines have a long shelf life (1 year or more), they are stored at a temperature of 2-10 C.

5-6 days before the introduction of live vaccines and 15-20 days after vaccination, antibiotics, sulfanilamide, nitrofuran preparations and immunoglobulins should not be used for treatment, as they reduce the intensity and duration of immunity.

Vaccines create active immunity in 7-21 days, which lasts up to 12 months on average.

Killed (inactivated) vaccines

To inactivate microorganisms, heating, treatment with formalin, acetone, phenol, ultraviolet rays, ultrasound, and alcohol are used. Such vaccines are not dangerous, they are less effective than live ones, but when they are repeatedly administered, they create a fairly strong immunity.

In the production of inactivated vaccines, it is necessary to strictly control the process of inactivation and at the same time preserve the set of antigens in the killed cultures.

Killed vaccines do not contain live microorganisms. The high efficiency of killed vaccines is associated with the preservation of a set of antigens in inactivated cultures of microorganisms that provide an immune response.

For the high efficiency of inactivated vaccines, the selection of industrial strains is of great importance. For the manufacture of polyvalent vaccines, it is best to use strains of microorganisms with a wide range of antigens, taking into account the immunological relationship of various serological groups and variants of microorganisms.

The spectrum of pathogens used for the preparation of inactivated vaccines is very diverse, but the most widespread are bacterial (vaccine against necrobacteriosis) and viral (anti-rabies inactivated dry cultural vaccine against rabies from the Schelkovo-51 strain.

Inactivated vaccines should be stored at 2-8°C.

Chemical vaccines

They consist of antigenic complexes of microbial cells connected with adjuvants. Adjuvants are used to enlarge antigenic particles, as well as to increase the immunogenic activity of vaccines. Adjuvants include aluminum hydroxide, alum, organic or mineral oils.

The emulsified or adsorbed antigen becomes more concentrated. When introduced into the body, it is deposited and comes from the injection site to organs and tissues in small doses. Slow resorption of the antigen prolongs the immune effect of the vaccine and significantly reduces its toxic and allergic properties.

Chemical vaccines include deposited vaccines against swine erysipelas and swine streptococcosis (serogroups C and R).

Associated vaccines

They consist of a mixture of cultures of microorganisms that cause various infectious diseases that do not inhibit the immune properties of each other. After the introduction of such vaccines, immunity is formed in the body against several diseases at the same time.

Anatoxins

These are drugs containing toxins, devoid of toxic properties, but retained antigenicity. They are used to induce immune responses aimed at neutralizing toxins.

Anatoxins are produced from exotoxins of various types of microorganisms. To do this, toxins are neutralized with formalin and kept in a thermostat at a temperature of 38-40 ° C for several days. Toxoids, in essence, are analogues of inactivated vaccines. They are cleaned of ballast substances, adsorbed and concentrated on aluminum hydroxide. Adsorbents are introduced into the toxoid to enhance adjuvant properties.

Anatoxins create antitoxic immunity, which persists for a long time.

Recombinant vaccines

Using genetic engineering methods, it is possible to create artificial genetic structures in the form of recombinant (hybrid) DNA molecules. A recombinant DNA molecule with new genetic information is introduced into the recipient's cell using carriers of genetic information (viruses, plasmids), which are called vectors.

Obtaining recombinant vaccines includes several stages:

• cloning of genes that provide the synthesis of the necessary antigens;
• introduction of cloned genes into a vector (viruses, plasmids);
• introduction of vectors into producer cells (viruses, bacteria, fungi);
• cultivation of cells in vitro;
• antigen isolation and purification or use of producer cells as vaccines.

The finished product must be tested against a natural reference drug or one of the first series of genetically engineered drug that has passed preclinical and clinical trials.

BG Orlyankin (1998) reports that a new direction in the development of genetically engineered vaccines has been created, based on the introduction of plasmid DNA (vector) with an integrated protective protein gene directly into the body. In it, plasmid DNA does not multiply, does not integrate into chromosomes and does not cause an antibody formation reaction. Plasmid DNA with an integrated protective protein genome induces a complete cellular and humoral immune response.

On the basis of a single plasmid vector, various DNA vaccines can be constructed by changing only the gene encoding the protective protein. DNA vaccines have the safety of inactivated vaccines and the efficacy of live ones. Currently, more than 20 recombinant vaccines have been designed against various human diseases: a vaccine against rabies, Aujeszky's disease, infectious rhinotracheitis, viral diarrhea, respiratory syncytial infection, influenza A, hepatitis B and C, lymphocytic choriomeningitis, human T-cell leukemia, herpesvirus infection person and others.

DNA vaccines have a number of advantages over other vaccines.

1. When developing such vaccines, it is possible to quickly obtain a recombinant plasmid carrying the gene encoding the necessary pathogen protein, in contrast to the long and expensive process of obtaining attenuated strains of the pathogen or transgenic animals.
2. Manufacturability and low cost of cultivation of the obtained plasmids in E. coli cells and its further purification.
3. The protein expressed in the cells of the vaccinated organism has a conformation as close as possible to the native one and has a high antigenic activity, which is not always achieved when using subunit vaccines.
4. Elimination of the vector plasmid in the body of the vaccinated occurs in a short period of time.
5. With DNA vaccination against particularly dangerous infections, the likelihood of disease as a result of immunization is completely absent.
6. Prolonged immunity is possible.

All of the above makes it possible to call DNA vaccines the vaccines of the 21st century.

However, the idea of ​​complete control of infections through vaccines was held until the late 1980s, when it was shaken by the AIDS pandemic.

DNA immunization is also not a universal panacea. Since the second half of the 20th century, infectious agents that cannot be controlled by immunoprophylaxis have become increasingly important. The persistence of these microorganisms is accompanied by the phenomenon of antibody-dependent increase in infection or integration of the provirus into the genome of the macroorganism. Specific prevention can be based on inhibition of pathogen penetration into sensitive cells by blocking recognition receptors on their surface (viral interference, water-soluble compounds that bind receptors) or by inhibiting their intracellular reproduction (oligonucleotide and antisense inhibition of pathogen genes, destruction of infected cells by a specific cytotoxin, etc.). ).

The problem of provirus integration can be solved by cloning transgenic animals, for example, by obtaining lines that do not contain provirus. Therefore, DNA vaccines should be developed against pathogens whose persistence is not accompanied by an antibody-dependent increase in infection or persistence of the provirus in the host genome.

Seroprophylaxis and serotherapy

Serums (Serum) form passive immunity in the body, which lasts 2-3 weeks, and is used to treat patients or prevent diseases in a threatened zone.

Immune sera contain antibodies, so they are most often used for therapeutic purposes at the onset of the disease in order to achieve the greatest therapeutic effect. Serums can contain antibodies against microorganisms and toxins, so they are divided into antimicrobial and antitoxic.

Serums are obtained at biofactories and biocombines by two-stage hyperimmunization of immunoserum producers. Hyperimmunization is carried out with increasing doses of antigens (vaccines) according to a certain scheme. At the first stage, the vaccine is administered (I-2 times), and then, according to the scheme in increasing doses, a virulent culture of the production strain of microorganisms is administered for a long time.

Thus, depending on the type of immunizing antigen, antibacterial, antiviral and antitoxic sera are distinguished.

It is known that antibodies neutralize microorganisms, toxins or viruses, mainly before they enter the target cells. Therefore, in diseases where the pathogen is localized intracellularly (tuberculosis, brucellosis, chlamydia, etc.), it has not yet been possible to develop effective methods of serotherapy.

Serum therapeutic and prophylactic drugs are used mainly for emergency immunoprophylaxis or the elimination of certain forms of immunodeficiency.

Antitoxic sera are obtained by immunizing large animals with increasing doses of antitoxins, and then toxins. The resulting sera are purified and concentrated, freed from ballast proteins, and standardized for activity.

Antibacterial and antiviral drugs are obtained by hyperimmunization of horses with appropriate killed vaccines or antigens.

The disadvantage of the action of serum preparations is the short duration of the formed passive immunity.

Heterogeneous sera create immunity for 1-2 weeks, globulins homologous to them - for 3-4 weeks.

Methods and procedure for administering vaccines

There are parenteral and enteral methods of introducing vaccines and sera into the body.

With the parenteral method, drugs are administered subcutaneously, intradermally and intramuscularly, which allows you to bypass the digestive tract.

One of the types of parenteral administration of biological products is aerosol (respiratory), when vaccines or sera are administered directly into the respiratory tract by inhalation.

The enteral method involves the introduction of biological products through the mouth with food or water. At the same time, the consumption of vaccines increases due to their destruction by the mechanisms of the digestive system and the gastrointestinal barrier.

After the introduction of live vaccines, immunity is formed in 7-10 days and persists for a year or more, and with the introduction of inactivated vaccines, the formation of immunity ends by the 10-14th day and its tension persists for 6 months.