The discovery of a vaccination method gave rise to new era fight against diseases.
The composition of the grafting material includes killed or greatly weakened microorganisms or their components (parts). They serve as a kind of dummy that trains the immune system to give the correct response to infectious attacks. The substances that make up the vaccine (inoculation) are not capable of causing a full-blown disease, but can enable the immune system to remember characteristic features microbes and when encountering a real pathogen, quickly identify and destroy it.
The production of vaccines became widespread at the beginning of the twentieth century, after pharmacists learned to neutralize bacterial toxins. The process of weakening potential infectious agents is called attenuation.
Today medicine has more than 100 types of vaccines against dozens of infections.
Based on their main characteristics, immunization preparations are divided into three main classes.
- Live vaccines. Protects against polio, measles, rubella, influenza, mumps, chickenpox, tuberculosis, rotavirus infection. The basis of the drug is weakened microorganisms - pathogens. Their strength is not enough to cause significant illness in the patient, but it is enough to develop an adequate immune response.
- Inactivated vaccines. Vaccinations against influenza, typhoid fever, tick-borne encephalitis, rabies, hepatitis A, meningococcal infection, etc. Contains dead (killed) bacteria or their fragments.
- Anatoxins (toxoids). Specially treated bacterial toxins. Based on them, vaccination material is made against whooping cough, tetanus, and diphtheria.
In recent years, another type of vaccine has appeared - molecular. The material for them is recombinant proteins or their fragments synthesized in laboratories using methods genetic engineering(recombinant vaccine against viral hepatitis B).
Schemes for the production of certain types of vaccines
Live bacterial
The regimen is suitable for BCG and BCG-M vaccines.
Live antiviral
The scheme is suitable for the production of vaccines against influenza, rotavirus, herpes degrees I and II, rubella, and chickenpox.
Substrates for growing viral strains during vaccine production can be:
- chicken embryos;
- quail embryonic fibroblasts;
- primary cell cultures (chicken embryonic fibroblasts, Syrian hamster kidney cells);
- continuous cell cultures (MDCK, Vero, MRC-5, BHK, 293).
The primary raw material is purified from cellular debris in centrifuges and using complex filters.
Inactivated antibacterial vaccines
- Cultivation and purification of bacterial strains.
- Biomass inactivation.
- For split vaccines, microbial cells are disintegrated and antigens are precipitated, followed by chromatographic isolation.
- For conjugate vaccines, antigens (usually polysaccharides) obtained during previous processing are brought closer to the carrier protein (conjugation).
Inactivated antiviral vaccines
- Substrates for growing viral strains in the production of vaccines can be chicken embryos, quail embryonic fibroblasts, primary cell cultures (chicken embryonic fibroblasts, Syrian hamster kidney cells), continuous cell cultures (MDCK, Vero, MRC-5, BHK, 293). Primary purification to remove cellular debris is carried out by ultracentrifugation and diafiltration.
- Ultraviolet light, formalin, and beta-propiolactone are used for inactivation.
- In the case of split or subunit vaccines, the intermediate product is exposed to a detergent to destroy the viral particles, and then specific antigens are isolated by thin chromatography.
- Human serum albumin is used to stabilize the resulting substance.
- Cryoprotectants (in lyophilisates): sucrose, polyvinylpyrrolidone, gelatin.
The scheme is suitable for the production of vaccination material against hepatitis A, yellow fever, rabies, influenza, polio, tick-borne and Japanese encephalitis.
Anatoxins
For decontamination harmful effects toxins using methods:
- chemical (treatment with alcohol, acetone or formaldehyde);
- physical (heating).
The scheme is suitable for the production of vaccines against tetanus and diphtheria.
According to the World Health Organization (WHO), infectious diseases account for 25% of total number deaths on the planet every year. That is, infections still remain on the list of the main reasons that end a person’s life.
One of the factors contributing to the spread of infectious and viral diseases is migration of population flows and tourism. The movement of human masses around the planet affects the level of health of the nation, even in such highly developed countries as the USA, the UAE and the European Union.
Based on materials: “Science and Life” No. 3, 2006, “Vaccines: from Jenner and Pasteur to the present day,” Academician of the Russian Academy of Medical Sciences V.V. Zverev, Director of the Research Institute of Vaccines and Serums named after. I. I. Mechnikova RAMS.
Ask a question to a specialist
Question for vaccination experts
Questions and answers
Is the Menugate vaccine registered in Russia? At what age is it approved for use?
Yes, the vaccine is registered - against meningococcus C, now there is also a conjugate vaccine, but against 4 types of meningococci - A, C, Y, W135 - Menactra. Vaccinations are carried out from 9 months of life.
The husband transported the RotaTek vaccine to another city. When buying it at the pharmacy, the husband was advised to buy a cooling container, and before the trip, freeze it in the freezer, then tie the vaccine and transport it that way. Travel time took 5 hours. Is it possible to administer such a vaccine to a child? It seems to me that if you tie the vaccine to a frozen container, the vaccine will freeze!
Answered by Kharit Susanna Mikhailovna
You are absolutely right if there was ice in the container. But if there was a mixture of water and ice, the vaccine should not freeze. However, live vaccines, which include rotavirus, do not increase reactogenicity at temperatures below 0, unlike non-live ones, and, for example, for live polio, freezing to -20 degrees C is allowed.
My son is now 7 months old.
At 3 months he developed Quincke's edema on Malyutka milk formula.
Hepatitis vaccination was given in the maternity hospital, the second at two months and the third yesterday at seven months. The reaction is normal, even without fever.
But we were verbally given a medical certificate for the DPT vaccination.
I am for vaccinations!! And I want to get vaccinated with DTP. But I want to make INFANRIX HEXA. We live in Crimea!!! It is nowhere to be found in Crimea. Please advise what to do in this situation. Maybe there is a foreign analogue? I absolutely don’t want to make it free. I want a high-quality cleaned one, so that there is as little risk as possible!!!
Infanrix Hexa contains a component against hepatitis B. The child is fully vaccinated against hepatitis. Therefore, Pentaxim vaccine can be made as a foreign analogue of DTP. In addition, it should be said that angioedema on formula milk is not a contraindication to the DTP vaccine.
Tell me, please, on whom and how are vaccines tested?
Polibin Roman Vladimirovich answers
Like all medications, vaccines undergo preclinical studies (in the laboratory, on animals), and then clinical studies on volunteers (on adults, and then on adolescents, children with the permission and consent of their parents). Before authorization for use in the national vaccination schedule, studies are carried out on a large number of volunteers, for example, the vaccine against rotavirus infection was tested on almost 70,000 in different countries peace.
Why is the composition of vaccines not presented on the website? Why is the annual Mantoux test still carried out (often not informative), and not a blood test, for example, the quantiferon test? How can one assert the immune response to an administered vaccine if no one yet knows in principle what immunity is and how it works, especially if we consider each individual person?
Polibin Roman Vladimirovich answers
The composition of vaccines is set out in the instructions for the drugs.
Mantoux test. According to Order No. 109 “On improving anti-tuberculosis measures in the Russian Federation” and Sanitary rules SP 3.1.2.3114-13 "Prevention of tuberculosis", despite the availability of new tests, children need to have the Mantoux test done annually, but since this test can give false positives, then if tuberculosis infection and active tuberculosis infection are suspected, the Diaskin test is performed. The Diaskin test is highly sensitive (effective) for detecting active tuberculosis infection (when mycobacteria are multiplying). However, phthisiatricians do not recommend completely switching to the Diaskin test and not doing the Mantoux test, since it does not “catch” early infection, and this is important, especially for children, since preventing the development of local forms of tuberculosis is effective precisely in early period infection. In addition, infection with Mycobacterium tuberculosis must be determined to decide on BCG revaccination. Unfortunately, there is not a single test that would answer the question with 100% accuracy of whether there is a mycobacterial infection or disease. The quantiferon test also detects only active forms of tuberculosis. Therefore, if infection or disease is suspected (positive Mantoux test, contact with a patient, complaints, etc.), complex methods are used (diaskin test, quantiferon test, radiography, etc.).
As for “immunity and how it works,” immunology is currently a highly developed science and much, in particular with regard to processes during vaccination, is open and well studied.
The child is 1 year and 8 months old, all vaccinations were given in accordance with the vaccination calendar. Including 3 Pentaxim and revaccination at one and a half years, also Pentaxim. At 20 months you should be diagnosed with polio. I’m always very worried and careful when choosing the right vaccinations, and now I’ve scoured the entire Internet, but I still can’t decide. We always gave an injection (in Pentaxim). And now the drops are talking. But live vaccine drops, I’m afraid of various side effects and think it’s better to play it safe. But I read that polio drops produce more antibodies, including in the stomach, that is, they are more effective than an injection. I'm confused. Explain, is the injection less effective (imovax-polio, for example)? Why are such conversations being held? I'm afraid the drops have, although minimal, the risk of complications in the form of illness.
Polibin Roman Vladimirovich answers
Currently, the National Vaccination Calendar of Russia assumes a combined vaccination regimen against polio, i.e. only the first 2 injections with inactivated vaccine and the rest with oral polio vaccine. This is due to the fact that it completely eliminates the risk of developing vaccine-associated polio, which is possible only during the first and in a minimal percentage of cases during the second administration. Accordingly, if there are 2 or more vaccinations against polio with an inactivated vaccine, complications with live polio vaccine are excluded. Indeed, it was believed and is recognized by some experts that the oral vaccine has advantages, since it forms local immunity on the intestinal mucosa, in contrast to IPV. However, it has now become known that the inactivated vaccine, to a lesser extent, also forms local immunity. In addition, 5 injections of polio vaccine, both oral live and inactivated, regardless of the level of local immunity on the intestinal mucous membranes, completely protect the child from paralytic forms of polio. In connection with the above, your child needs to do the fifth OPV vaccination or IPV.
It should also be said that today the World Health Organization’s global plan to eradicate polio in the world is being implemented, which involves a complete transition of all countries to an inactivated vaccine by 2019.
Our country already has a very long history of using many vaccines - are there long-term studies of their safety and is it possible to get acquainted with the results of the impact of vaccines on generations of people?
Olga Vasilievna Shamsheva answers
Over the past century, people's life expectancy has increased by 30 years, of which people gained 25 additional years of life through vaccination. More people survive, they live longer and have better lives due to the fact that disability due to infectious diseases has decreased. This is a general response to how vaccines affect generations of people.
The World Health Organization (WHO) website has extensive factual material on the beneficial effects of vaccination on the health of individuals and humanity as a whole. Let me note that vaccination is not a belief system, it is an area of activity based on a system scientific facts and data.
On what basis can we judge the safety of vaccination? Firstly, side effects and adverse events are recorded and identified and their cause-and-effect relationship with the use of vaccines is determined (pharmacovigilance). Secondly, important role Post-marketing studies (possible delayed adverse effects of vaccines on the body) conducted by companies holding registration certificates play a role in tracking adverse reactions. Finally, the epidemiological, clinical and socioeconomic effectiveness of vaccination is assessed through epidemiological studies.
As far as pharmacovigilance is concerned, our pharmacovigilance system in Russia is just being formed, but is demonstrating very high rates of development. In just 5 years, the number of registered reports of adverse reactions for medicines in the “Pharmaconadzor” subsystem of the AIS of Roszdravnadzor increased 159 times. 17,033 complaints in 2013 versus 107 in 2008. For comparison, in the United States, data is processed about 1 million cases per year. The pharmacovigilance system allows you to monitor the safety of drugs; statistical data is accumulated, on the basis of which the instructions for use may change. medical use drug, the drug may be withdrawn from the market, etc. This ensures patient safety.
And according to the law “On Treatment medicines» from 2010, doctors are required to report to federal regulatory authorities about all cases of side effects of drugs.
Immunoprophylaxis for the majority serious illnesses involves the introduction of a specific biological substance that forms the body’s defense against a specific pathology. Modern pharmacology offers various types of vaccines that cost dozens of funds.
Each of them has an original method of preparation, effectiveness and impact.
The basic classification of vaccines provides two types of substances: traditional, belonging to the 1st and 2nd generation; the latest, created thanks to biotechnology and related to III.
Based on the nature of the antigen, there is also a division into two groups: bacterial and viral.
I and II include live and killed - inactivated vaccines.
III represent:
- genetic engineering;
- synthetic;
- molecular;
- conjugated;
- split vaccines.
All types of vaccines are divided into separate subtypes.
Live vaccines
The following strains can act as the main active component of such a drug:
- Attenuated- created from organisms with low pathogenicity, but a strong challenge immune response. Imitation of the disease occurs in a weak form, which occurs quickly, sparingly severe symptoms or without them.
- Divergent- microorganisms are used that are related to infectious pathogens, but are neutral. Their antigens provoke an immune response, but without the formation of a full-fledged disease.
- Recombined or vector- are based on harmless organisms with implanted particles of antigens of pathogenic bacteria. This strain, after entering the body, begins to form specific immunity.
Interesting! The recombined vaccine most often uses DNA from smallpox, salmonella, hepatitis B, tick-borne encephalitis, etc.
The disadvantages include the threat of manifest infection due to a decrease in the harmlessness of the selected strain. The disease manifests itself in the patient quite quickly.
Inactivated
The main difference from the previous type is that serum contains dead microorganisms that can no longer reproduce, but provoke a reaction in the body that forms protection against the disease. The most common vaccines of this type are polio and pertussis whole cell.
The drug exhibits less immunogenicity, which necessitates repeated administration. But the absence of ballast in the form of substances accompanying the vital activity of bacteria significantly reduces the likelihood of side effects.
Inactivated ones are divided into:
- Corpuscular drugs have a full set of antigens, but do not pose a danger in the form of a risk of developing the disease. Prepared from killed organisms that have been killed by heat or chemical treatment.
- Subunit (component) microorganisms are not made up of whole microorganisms, but individual particles of their DNA that can cause a protective reaction in human body. To isolate basic materials, physical and chemical methods are used, which is why they are also called chemical. To forcibly increase immunogenicity, the active ingredient is combined with adjuvants that adsorb on aluminum hydroxide.
Example: Vaccination of cattle, live dry vaccine against large rhinotracheitis cattle, parainfluenza-3 (PG-3), respiratory syncytial infection and pasteurellosis.
Genetic engineering
The DNA of pathogens for such substances is obtained through the use of genetic engineering and contains exclusively highly immunogenic particles.
Creation methods:
- According to the principle of preparing vector vaccines, genes of high virulence are added to non-pathogenic or weakly pathogenic microorganisms.
- Introducing DNA that causes an immunoreaction into unrelated bacteria. Then antigens are isolated and used as the main component.
- Virulent genes are artificially removed, and modified organisms are used in corpuscular preparations. This selection makes it possible to obtain stably attenuated strains of many bacteria and polyvalent vaccines.
Synthetic
During preparation, the substance releases nucleic acids or polypeptides, which form determinants hostile to the body, which are recognized by it with the help of antibodies. Among the obligatory components of synthetic serums are the pathogen antigen, a high molecular weight carrier and an adjuvant.
The resulting drug is as safe as possible relative to the likelihood of complications after vaccine therapy.
But there are factors that hinder mass production:
- It is rarely possible to find data on the compatibility of a synthetic epitope with a specific natural antigen;
- low molecular weight compounds have poor immunogenicity, which requires individual selection of an amplifier.
But these substances are the best option for vaccinating people with impaired immune status.
Molecular
Preparations in which the key component is toxoids - neutralized by formaldehyde and heat treatment, completely losing their toxic function, but retaining the DNA to which the immune system reacts.
Available in the form:
- Mono-vaccines- are used to create immunity to one particular pathogen.
- Associated drugs(CPC) - used to simultaneously form protection against many diseases: DTP, ADS, tetravaccine.
Mainly used for the prevention of botulism, diphtheria, staphylococcal infection and tetanus.
Conjugated
Complex combination of antigens at the level of polysaccharides and toxins. Recent developments are aimed at attempts to synthesize an acellular vaccine, which will include toxoids and other pathogenicity factors, but will be as safe as possible for humans.
Currently, vaccines against pneumococcus and Haemophilus influenzae have been created based on this technique.
Split or split vaccines
There is also a separate type of vaccinations that are associated with animal diseases that can be transmitted to people. The main task of such immunization is to protect a person from a dangerous disease that he can get from a dog, cat or other animals, even birds, that are carriers. Basically, such measures are relevant for those who are involved in the disposal or breeding of animals in livestock and poultry farming, work in veterinary medicine, etc. The most common disease is rabies.
Interesting fact! Scientist Louis Pasteur created a vaccine against anthrax and a rabies vaccination, and he himself soon died of uremia. After an autopsy, it was discovered that his brain was almost destroyed.
What are the methods of administration?
In medicine, the term “vaccination” has the following definition: inoculation of an antigenic substance that can cause a protective reaction of the body in order to form immunity to a specific disease.
Drugs are administered according to the type of substance according to the instructions provided by the manufacturer.
Immunology has the following capabilities:
- Intramuscularly. The injection area varies depending on the patient’s age: in children under 1 year - top part hips; Children from 2 years of age and adults are injected mainly into the deltoid muscle, located in the upper part of the shoulder. The method is relevant for inactivated drugs, which include: DTP, against hepatitis B, ADS, against influenza.
Important! According to reviews from parents, infants tolerate vaccination in the thigh more easily than in the buttock.
Pediatric doctors justify this by saying that sciatic nerves sometimes have an abnormal location, which occurs in approximately 5% of children. Moreover, the substance, due to the large fat layer on the butt, often does not enter the muscle, which significantly reduces the effectiveness of the vaccine.
- Subcutaneously- is injected into the deltoid muscle with a special thin needle. Practical example: smallpox vaccination, BCG.
- Cutaneously and intradermally- method for living preparations. distribution of which throughout the body is undesirable due to high risk post-vaccination complication. Suitable for BCG, tularemia, smallpox, brucellosis.
- Intranasally- a method for vaccines in the form of a cream, spray or ointment that form immunity against rubella or measles.
- Orally- the substance is dripped into the oral cavity. The most common type is polio (OPV).
Each vaccination method is relevant for a specific type of drug, its characteristics and the age of the patient in order to maximize the effect.
Interesting! The very concept of “vaccine” implies a combined protective medicinal substance against infectious diseases.
Each country has its own vaccination calendar, and they should be carried out only according to it. This condition is met due to the individual epidemiological situation, which is typical for one region, but ineffective for another.
The national calendar of preventive vaccinations can be obtained from the clinic to which the patient is assigned.
The Russian schedule is less intense than, for example, the USA or European countries.
Vaccination table by age 2018
| Age | Name |
| Newborns and 1 day | I hepatitis B |
| 1 Week | BCG |
| 1 month | II hepatitis B |
| 2 months | I pneumococcus |
| 3 months | I diphtheria, whooping cough; I polio; I hemophilus influenzae infection (HR*) |
| 4.5 months | II diphtheria, whooping cough; II hemophilus influenzae infection (HI); II polio; II pneumococcus |
| Six months | III diphtheria, whooping cough, tetanus; III hepatitis B; III polio; III hemophilus influenzae infection (HI) |
| 1 year | ZhPKV; IV hepatitis B (HR); chicken pox |
| 1 year 3 months | Revaccination of pneumococcus |
| 1.5 years | I revaccination of polio; I diphtheria, whooping cough, tetanus; revaccination of Haemophilus influenzae infection (HIB) (HR) |
| 1 year and 8 months. | II revaccination of polio |
| From 3 to 6 years | Hepatitis A |
| 6 years | Revaccination of ZhPKV |
| From 6 to 7 years | II revaccination of diphtheria, tetanus; BCG revaccination |
| Girls from 12 to 13 years old | Human papillomavirus. |
| From 14 years old | III revaccination of diphtheria, tetanus; III revaccination polio. |
| From 18 years old | Revaccination of diphtheria, tetanus every 10 years from the last procedure. |
| From 1 year to 18 years, women from 18 to 25 years and without information about vaccination availability | Rubella |
| Children from 1 to 18 years of age, adults up to 35 years of age: unvaccinated or without information about vaccination. From 36 to 55 years old GR, health workers and everyone who is required by duty. | Measles, measles revaccination. |
| Children from six months of age, students from grades 1 to 11, students, adult employees of government organizations, persons with chronic illnesses associated with cardiovascular, respiratory system, metabolism. | Seasonal flu, ARVI |
*Risk group - find out whether a particular patient belongs to this type of people from a local therapist.
Contraindications to vaccination
Vaccination can only be done healthy person. Therefore, before administering the drug, the doctor will definitely prescribe the appropriate tests or conduct a diagnostic examination.
Important! In case of deliberate concealment of an illness that may conflict with the administered vaccine, the doctor is relieved of responsibility for complications arising from this.
There are two groups of contraindications:
- A number of chronic pathological conditions which prohibit vaccination on permanent basis, but they are extremely rare - 1%.
- An exacerbation of the disease may temporarily delay receiving the vaccine for a short period until recovery. IN in this case, especially in relation to children, it is customary to use the term “medical outlet”.
Indications for prohibiting or temporarily postponing the procedure are differentiated for each drug individually by the doctor.
Possible complications after the vaccine
The post-vaccination reaction is characterized by a temporary change in the functioning of the body, most often subjectively assessed by the patient himself. Sometimes the condition is considered as borderline between healthy and pathological. Changes in indicators are insignificant, but they do occur.
A complication is an uncomfortable or life-threatening reaction that differs in intensity from most of the usual ones that are characteristic of the administered substance.
Subdivided pathological processes on the:
- post-vaccination complication as a direct consequence of the therapy;
- production - arising due to an error in the creation of the vaccine or its delivery or storage;
- exacerbation of a chronic disease that arose due to a pathogen added after vaccination;
- another intercurrent infection that has entered the body, the immunity of which is aimed at forming protection against the introduced antigens.
Each drug has a number side effects which occur in most patients. The physician should be familiar with them before the procedure. Anything that occurs above the designated norm is a complication or an atypical post-vaccination reaction. In this case, it is recommended to consult a doctor immediately.
Vaccine classification
By purpose Vaccines are divided into preventive and therapeutic.
According to the nature of the microorganisms from which they are created, There are types of wakiins:
- bacterial;
- viral;
- rickettsial.
There are mono- and polyvaccines - prepared from one or more pathogens, respectively.
By cooking method vaccines are distinguished:
- alive;
- killed;
- combined.
To increase immunogenicity, various types of adjuvants (aluminum-potassium alum, aluminum hydroxide or phosphate, oil emulsion) are sometimes added to vaccines, creating a depot of antigens or stimulating phagocytosis and thus increasing the foreignness of the antigen for the recipient.
Live vaccines
contain live attenuated strains of pathogens with sharply reduced virulence or strains of microorganisms that are non-pathogenic to humans and closely related to the pathogen in antigen terms (divergent strains). These also include recombinant (genetically engineered) vaccines containing vector strains of non-pathogenic bacteria/viruses (genes responsible for the synthesis of protective antigens of certain pathogens have been introduced into them using genetic engineering methods).
Examples genetically engineered vaccines The hepatitis B vaccine, Engerix B, and the rubella measles vaccine, Recombivax NV, can be used.
Since live vaccines contain strains of pathogenic microorganisms with sharply reduced virulence, they essentially reproduce a mild infection in the human body, but do not 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 quite intense and long-lasting 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 BCGitis after administration of the BCG vaccine.
Live vakiins are used for the prevention of:
- tuberculosis;
- especially dangerous infections(plague, anthrax, tularemia, brucellosis);
- influenza, measles, rabies (anti-rabies);
- mumps, smallpox, polio (Seibin-Smorodintsev-Chumakov vaccine);
- yellow fever, rubella measles;
- Q fever.
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 ones. Therefore, the immunity they evoke is short-lived and relatively less intense. Killed vakiins are used for the prevention of:
- whooping cough, leptospirosis,
- typhoid fever, paratyphoid A and B,
- cholera, tick-borne encephalitis,
- polio (Salk vaccine), hepatitis A.
Killed vaccines also include chemical vaccines containing certain chemical components of pathogens that are immunogenic (subcellular, subvirion). 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. Anti-idiotypic vaccines are also known, which are also classified as killed vaccines. These are antibodies to one or another idiotype of human antibodies (anti-antibodies). Their active center is similar to the determinant group of the antigen that caused the formation of the corresponding idiotype.
Combination vaccines
To combination vaccines include artificial vaccines.
They are preparations consisting of a microbial antigenic component (usually isolated and purified or artificially synthesized pathogen antigen) and synthetic polyions (polyacrylic acid, etc.) - powerful stimulators of the immune response. They differ from chemically killed vaccines in the content of these substances. The first such domestic vaccine, the influenza polymer-subunit vaccine (“Grippol”), developed at the Institute of Immunology, has already been put into practice Russian healthcare. For specific prevention For infectious diseases whose pathogens produce exotoxin, toxoids are used.
Anatoxin is an exotoxin that is devoid of toxic properties, but retains antigenic properties. Unlike vaccines, when used in humans, antimicrobial immunity is formed, when toxoids are administered, antitoxic immunity is formed, since they induce the synthesis of antitoxic antibodies - antitoxins. Currently used:
- diphtheria;
- tetanus;
- botulinum;
- staphylococcal toxoids;
- Cholerogen toxoid.
Examples of associated vaccines are:
— DTP vaccine (adsorbed pertussis-diphtheria-tetanus vaccine), in which the pertussis component is represented by killed pertussis vaccine, and diphtheria and tetanus by corresponding toxoids;
— TAVTe vaccine containing O-antigens of typhoid, paratyphoid A- and B-bacteria and tetanus toxoid; typhoid chemical vaccine with sextaanatoxin (a mixture of toxoids of Clostridia botulism types A, B, E, Clostridium tetanus, Clostridium perfringens type A and edematiens - the last 2 microorganisms are the most common causative agents of gas gangrene), etc.
At the same time, DPT (diphtheria-tetanus toxoid), often used instead of DTP when vaccinating children, is simply a combination drug and not an associated vaccine, since it contains only toxoids.
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The arsenal of modern immunoprophylaxis includes several dozen immunoprophylactic agents.
There are currently two types of vaccines:
- traditional (first and second generation) and
- third generation vaccines designed based on biotechnology methods.
First and second generation vaccines
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Among first and second generation vaccines distinguish:
- alive,
- inactivated (killed) and
- chemical vaccines.
Live vaccines
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To create live vaccines, microorganisms (bacteria, viruses, rickettsia) with weakened virulence that arose in natural conditions or artificially in the process of strain selection. The effectiveness of a live vaccine was first shown by the English scientist E. Jenner (1798), who proposed a vaccine containing a pathogen that is low virulent for humans for immunization against smallpox cowpox, from the Latin word vassa - cow, the name “vaccine” comes from. In 1885 L. Pasteur proposed against rabies live vaccine from a weakened (attenuated) vaccine strain. To reduce virulence, French researchers A. Calmette and C. Guerin cultivated bovine mycobacterium tuberculosis for a long time in an environment unfavorable for the microbe, which is used to obtain the live BCG vaccine.
In Russia, both domestic and foreign live attenuated vaccines are used. These include vaccines against polio, measles, mumps, rubella, and tuberculosis, which are included in the preventive vaccination calendar.
Vaccines against tularemia, brucellosis, anthrax, plague, yellow fever, and influenza are also used. Live vaccines create intense and long-lasting immunity.
Inactivated vaccines
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Inactivated (killed) vaccines are preparations prepared using industrial strains of the pathogens of the corresponding infections and preserving the corpuscular structure of the microorganism. (The strains have full antigenic properties.) There are various methods inactivation, the main requirements for which are reliability of inactivation and minimal damaging effect on antigens of bacteria and viruses.
Historically, heating was considered the first method of inactivation. (“warmed vaccines”).
The idea of “warmed vaccines” belongs to V. Collet and R. Pfeiffer. Inactivation of microorganisms is also achieved under the influence of formaldehyde, formaldehyde, phenol, phenoxyethanol, alcohol, etc.
The Russian vaccination calendar includes vaccination with killed whooping cough vaccine. Currently, the country uses (along with live) inactivated polio vaccine.
In healthcare practice, along with live ones, killed vaccines against influenza, tick-borne encephalitis, typhoid fever, paratyphoid fever, brucellosis, rabies, hepatitis A, meningococcal infection, herpetic infection, Q fever, cholera and other infections.
Chemical vaccines
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Chemical vaccines contain specific antigenic components extracted from bacterial cells or toxins by various methods (extraction with trichloroacetic acid, hydrolysis, enzymatic digestion).
The highest immunogenic effect is observed with the introduction of antigenic complexes obtained from the shell structures of bacteria, for example, the Vi-antigen of typhoid and paratyphoid pathogens, the capsular antigen of the plague microorganism, antigens from the shells of the pathogens of whooping cough, tularemia, etc.
Chemical vaccines have less pronounced side effects, they are reactogenic, and remain active for a long time. Among the drugs in this group, cholerogens are used in medical practice - toxoid, highly purified antigens of meningococci and pneumococci.
Anatoxins
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To create artificial active immunity Toxoids are used against infectious diseases caused by microorganisms that produce exotoxin.
Anatoxins are neutralized toxins that have retained antigenic and immunogenic properties. Neutralization of the toxin is achieved by exposure to formaldehyde and prolonged exposure in a thermostat at a temperature of 39–40 ° C. The idea of neutralizing the toxin with formalin belongs to G. Ramon (1923), who proposed diphtheria toxoid for immunization. Currently, diphtheria, tetanus, botulinum and staphylococcal toxoids are used.
In Japan, an acellular precipitated purified pertussis vaccine has been created and is being studied. It contains lymphocytosis-stimulating factor and hemagglutinin as toxoids and is significantly less reactogenic and at least as effective as corpuscular killed pertussis vaccine (which is the most reactogenic part of the widely used DTP vaccine).
Third generation vaccines
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Improvement is currently ongoing traditional technologies production of vaccines and vaccines are successfully developed taking into account the achievements of molecular biology and genetic engineering.
The impetus for the development and creation of third-generation vaccines was due to the limited use of traditional vaccines for the prevention of a number of infectious diseases. First of all, this is due to pathogens that are poorly cultivated in in vitro and in vivo systems (hepatitis viruses, HIV, malaria pathogens) or have pronounced antigenic variability (influenza).
Third generation vaccines include:
- synthetic vaccines,
- genetic engineering And
- anti-idiotypic vaccines.
Artificial (synthetic) vaccines
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Artificial (synthetic) vaccines are a complex of macromolecules that carry several antigenic determinants of various microorganisms and are capable of immunizing against several infections, and a polymer carrier is an immunostimulant.
The use of synthetic polyelectrolytes as an immunostimulant can significantly increase the immunogenic effect of the vaccine, including in individuals carrying low response Ir genes and strong suppression Is genes, i.e. in cases where traditional vaccines are ineffective.
Genetically engineered vaccines
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Genetically engineered vaccines are developed based on antigens synthesized in recombinant bacterial systems (E. coli), yeast (Candida) or viruses (vaccinia virus). This type of vaccine may be effective in immunoprophylaxis of viral hepatitis B, influenza, herpes infection, malaria, cholera, meningococcal infection, and opportunistic infections.
Anti-idiotypic vaccines
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Among the infections for which vaccines already exist or the use of new generation vaccines is planned, hepatitis B should be noted first of all (vaccination was introduced in accordance with the order of the Ministry of Health of the Russian Federation No. 226 of 06/08/96 in the vaccination calendar).
Promising vaccines include vaccines against pneumococcal infection, malaria, HIV infection, hemorrhagic fevers, acute respiratory viral infections (adenovirus, respiratory syncytial virus infection), intestinal infections(rotavirus, helicobacteriosis), etc.
Single and combination vaccines
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Vaccines may contain antigens from one or more pathogens.
Vaccines containing antigens of the causative agent of one infection are called monovaccines(cholera, measles monovaccine).
Widely used associated vaccines consisting of several antigens and allowing vaccination against several infections simultaneously, di- And trivaccines. These include adsorbed pertussis-diphtheria-tetanus (DPT) vaccine, typhoid-paratyphoid-tetanus vaccine. Adsorbed diphtheria-tetanus (DT) divaccine is used, which is vaccinated in children after 6 years of age and adults (instead of DTP vaccination).
Live associated vaccines include the measles, rubella, and mumps vaccine (MMR). A combined TTK and chickenpox vaccine is being prepared for registration.
Ideology of creation combined vaccines are included in the World Vaccine Initiative program, the ultimate goal of which is to create a vaccine that could protect against 25-30 infections, would be administered once orally at a very early age and would not cause side effects.
