It was thanks to vaccination that humanity began to rapidly survive and reproduce. Opponents of vaccines do not die from plague, measles, smallpox, hepatitis, whooping cough, tetanus and other scourges only because civilized people, with the help of vaccines, have practically destroyed these diseases in the bud. But this does not mean that there is no longer a risk of getting sick and dying. Read about which vaccines you need.
History knows many examples where diseases caused devastating damage. Plague in the 14th century wiped out a third of Europe's population, the Spanish Flu of 1918-1920 killed an estimated 40 million people, and a smallpox epidemic left fewer than 3 million of the 30 million Incan population.
It is obvious that the advent of vaccines has made it possible to save millions of lives in the future - this can be seen simply by the growth rate of the world's population. Edward Jenner is considered a pioneer in the field of vaccination. In 1796, he noticed that people working on farms with cows infected with cowpox did not get sick smallpox. To confirm, he grafted cowpox the boy and proved that he was no longer susceptible to infection. This subsequently became the basis for the eradication of smallpox throughout the world.
What vaccines are there?
The vaccine contains killed or greatly weakened microorganisms in small quantities, or their components. They cannot cause a full-fledged disease, but they allow the body to recognize and remember their characteristics, so that later, when encountering a full-fledged pathogen, it can be quickly identified and destroyed.
Vaccines are divided into several main groups:
Live vaccines. For their production, weakened microorganisms are used that cannot cause disease, but help develop the correct immune response. Used to protect against polio, influenza, measles, rubella, mumps, chickenpox, tuberculosis, rotavirus infection, yellow fever and etc.
Inactivated vaccines . Made from killed microorganisms. In this form, they cannot reproduce, but cause the development of immunity against the disease. An example is inactivated polio vaccine, whole cell pertussis vaccine.
Subunit vaccines . The composition includes only those components of the microorganism that cause the development of immunity. An example is vaccines against meningococcal, Haemophilus influenzae, and pneumococcal infections.
Anatoxins . Neutralized toxins of microorganisms with the addition of special enhancers - adjuvants (aluminum salts, calcium). Example – vaccines against diphtheria, tetanus.
Recombinant vaccines . Created using methods genetic engineering, which include recombinant proteins synthesized in laboratory strains of bacteria and yeast. An example is the hepatitis B vaccine.
Vaccinal prophylaxis is recommended to be carried out in accordance with the National Vaccination Calendar. It is different in each country, since the epidemiological situation may differ significantly, and in some countries the vaccinations used in others are not always necessary.
Here national calendar preventive vaccinations in Russia:
You can also familiarize yourself with the US vaccination calendar and vaccination calendar European countries- they are in many ways very similar to the domestic calendar:
- Vaccination calendar in the European Union (you can select any country from the menu and view the recommendations).
Tuberculosis
Vaccines – “BCG”, “BCG-M”. They do not reduce the risk of contracting tuberculosis, but they prevent up to 80% in children severe forms infections. Included in the national calendar of more than 100 countries around the world.
Hepatitis B
Vaccines – “Euvax B”, “Recombinant hepatitis B vaccine”, “Regevac B”, “Engerix B”, “Bubo-Kok” vaccine, “Bubo-M”, “Shanvak-V”, “Infanrix Hexa”, “ DPT-GEP B.”
With the help of these vaccines, it was possible to reduce the number of children with chronic form hepatitis B from 8-15% to<1%. Является важным средством профилактики, защищает от развития первичного рака печени. Предотвращает 85-90% смертей, происходящих вследствие этого заболевания. Входит в календарь 183 стран.
Pneumococcal infection
Vaccines – “Pneumo-23”, 13-valent “Prevenar 13”, 10-valent “Synflorix”.
Reduces the incidence of pneumococcal meningitis by 80%. Included in the calendar of 153 countries.
Diphtheria, whooping cough, tetanus
Vaccines - combined (contain 2-3 vaccines in 1 preparation) - ADS, ADS-M, AD-M, DPT, "Bubo-M", "Bubo-Kok", "Infanrix", "Pentaxim", "Tetraxim", "Infanrix Penta", "Infanrix Hexa"
Diphtheria – the effectiveness of modern vaccines is 95-100%. For example, the risk of getting encephalopathy in unvaccinated people is 1:1200, and in vaccinated people it is less than 1:300,000.
Whooping cough – vaccine effectiveness is more than 90%.
Tetanus – 95-100% effective. Persistent immunity lasts 5 years, after which it gradually fades, which is why revaccination is required every 10 years.
194 countries of the world are included in the calendar.
Polio
Vaccines: Infanrix Hexa, Pentaxim, oral polio vaccine types 1, 3, Imovax Polio, Poliorix, Tetraxim.
Poliomyelitis is incurable, it can only be prevented. After the introduction of vaccination, the number of cases fell from 350,000 cases since 1988 to 406 cases in 2013.
Haemophilus influenzae infection
Vaccines: Act-HIB, Hiberix Pentaxim, Haemophilus influenzae type B conjugate, Infanrix Hexa.
Children under 5 years of age cannot independently adequately form immunity to this infection, which is highly resistant to antibacterial drugs. The effectiveness of vaccination is 95-100%. Included in the calendar of 189 countries.
Measles, rubella, mumps
Vaccines: Priorix, MMP-II.
Measles vaccination prevented 15.6 million deaths between 2000 and 2013. Global mortality fell by 75%.
Rubella is tolerated by children without any problems, but in pregnant women it can cause fetal malformations. Mass vaccination in Russia has reduced the incidence to 0.67 per 100,000 people. (2012).
Mumps - can cause a large number of complications, such as deafness, hydrocephalus, and male infertility. The effectiveness of vaccination is 95%. Incidence cases for 2014 in Russia – 0.18 per 100,000 people.
Flu
Vaccines: "Ultravac", "Ultrix", "Microflu", "Fluvaxin", "Vaxigrip", "Fluarix", "Begrivac", "Influvac", "Agrippal S1", "Grippol plus", "Grippol", "Inflexal" V", "Sovigrip".
The vaccine works in 50-70% of cases. Indicated for people at risk (the elderly, those with concomitant respiratory pathologies, weakened immunity, etc.).
Note: Russian vaccines “Grippol” and “Grippol +” have an insufficient amount of antigens (5 mcg instead of the required 15), justifying this by the presence of polyoxidonium, which should stimulate the immune system and enhance the effect of the vaccine, but there is no data confirming this.
What are the negative consequences of using vaccines?
Negative consequences can be divided into side effects and post-vaccination complications.
Side effects are reactions to drug administration that do not require treatment. Their risk is less than 30%, like most drugs.
The list of “side effects”, if summed up for all vaccines:
- An increase in body temperature for several days (can be controlled with Ibuprofen; Paracetamol is not recommended due to a possible decrease in the effect of vaccination).
- Pain at the injection site for 1-10 days.
- Headache.
- Allergic reactions.
However, there are also more dangerous, although extremely rare, manifestations that should be treated by the attending physician:
- Vaccine-associated polio. There was 1 case per 1-2 million vaccinations. At the moment, thanks to the new inactivated vaccine, it does not occur at all.
- Generalized BCG infection is the same probability. Occurs in newborns with immunodeficiency.
- Cold abscess - from BCG, about 150 cases per year. Occurs due to improper administration of the vaccine.
- Lymphadenitis - BCG, about 150 cases per year. Inflammation of regional lymph nodes.
- Osteitis - Damage to the BCG bone, mainly the ribs. Less than 70 cases per year.
- Infiltrates - compactions at the injection site, from 20 to 50 cases per year.
- Encephalitis - from live vaccines such as measles, rubella, mumps, is extremely rare.
Like any working drug, vaccines can have a negative effect on the body. However, these effects are incredibly small compared to the benefits.
Do not self-medicate and take care of your health.
Vaccines are immunobiological preparations for the immunoprophylaxis of infectious diseases by developing an active immune response to a specific pathogen. Vaccines help create long-term resistance of the body to a certain type of pathogenic microbial bodies. Vaccines help carry out routine and emergency prevention of infectious diseases, which is called vaccination. This effective and at the same time simple technique quickly gained respect among specialists. It serves to prevent epidemics that threaten the health of all humanity.
The essence of vaccination
Vaccination is a plan of action aimed at protecting the body of an adult or child from harmful microorganisms. The method is based on the ability of immunobiological solutions to train the immune system by remembering infectious agents or toxoids and instantly destroying them during subsequent infection.
Vaccination is a multi-level action, conditionally divided into several stages:
- identification of persons for whom vaccination is recommended;
- choice of vaccine preparation (live, inactivated, toxoid);
- scheduling vaccinations;
- administration of vaccines according to the approved plan;
- control of results;
- prevention and treatment of possible post-vaccination complications or adverse reactions (most often pathological reactions are observed after the administration of tetanus toxoids, diphtheria bacillus in combination with a pertussis component).
Modern vaccines are highly effective and reliable preparations with specific antigens (microorganisms, their fragmentary parts, toxoids) for the prevention of dangerous infectious pathologies and other diseases. They are created through the use of modern genetic engineering developments. They contribute to the rapid formation of protective resistance to various types of painful conditions. Vaccines can be used for vaccine therapy of infection after patient contact with a potential pathogen.
Basic methods of immunization
Vaccination methods depend on the method of administering a prophylactic solution with antigens to a person. A number of these techniques are used in clinical practice. Depending on their characteristics, it is determined how the immune response will be instilled:
- the intramuscular method requires an injection into the muscles of the thigh and delta (a striking example is vaccination with DTP toxoids);
- subcutaneous vaccinations are placed in the subscapular or shoulder region (this vaccination option is characterized by increased effectiveness, low allergenicity, and ease of use);
- intradermal vaccine injections are carried out with a live vaccine (BCG, plague, tularemia, Q fever);
- the inhalation method is used for emergency care (vaccines against tetanus, influenza, diphtheria intoxication, rubella, and tuberculosis are administered this way);
- oral administration is one of the most convenient immunization options, since the drugs are administered through the mouth in the form of drops (rabies vaccination, polio vaccine).
Intramuscular, subcutaneous, and intradermal vaccinations are the most unpleasant for patients, as they are administered by puncturing the skin, causing pain to the person. To eliminate discomfort, today it is recommended to administer drugs in the form of aerosols or orally. In addition to being painless, these methods of preventive immunization are characterized by high sterility and a small number of post-vaccination complications.
Vaccine classification
Depending on the origin, there are four types of vaccines:
- live vaccine consisting of weakened pathogens;
- inactivated suspension, which includes killed microorganisms or their fragments;
- a chemical vaccine contains highly purified antigens;
- a synthetic vaccine synthesized using advanced genetic engineering technologies in the field of microbiology.
Some vaccines consist of components that promote the development of immunity against one disease (single-drug). Others include active ingredients that protect against several pathologies at once, which is why they are called combination vaccines.
If we take into account the type of antigens involved in creating the vaccine, then it is easy to identify the types of solutions:
- containing whole microbial cellular elements (live or inactivated vaccine);
- including fragments of microbial units;
- consisting of microorganism toxins (anatoxins);
- created on the basis of synthetic antigens;
- obtained by synthesizing antigens using the achievements of genetic engineering.
What is a live vaccine?
A classic live vaccine is a means of immunoprophylaxis, in the manufacturing process of which not completely killed, but weakened strains of pathogenic agents were used. These drugs have pronounced immunogenic properties, but are not able to provoke the development of the disease with its inherent symptoms.
The introduction of this type of vaccine provokes the formation of protective complexes related to persistent cellular, humoral or secretory immunity. These suspensions often cause complications, unlike toxoids, which are much better accepted by the immune system.
Advantages and disadvantages
Among the advantages of vaccines created using live, that is, not killed, microbial agents are:
- high efficiency;
- rapid formation of immune complexes;
- the absence of any preservatives in the composition of the drug;
- use of minimum concentrations of vaccines;
- the possibility of using different grafting methods;
- activation of different types of immunity;
- low cost and availability.
The live vaccine, in addition to its advantages, also has its disadvantages. The main disadvantages include:
- the ability to provoke the development of pathology when vaccinating a patient with a weakened immune system;
- vaccines based on live pathogens are unstable and quickly lose their positive qualities with temperature changes (people experience undesirable effects of immunization precisely after the introduction of low-quality vaccines);
- a live vaccine cannot be combined with other means of vaccine prophylaxis (such actions are fraught with loss of effect from the drugs or the appearance of allergies).
Types of live vaccine suspensions
Immunologists take into account the properties of vaccine components with live microbes, dividing them into attenuated and divergent suspensions. Attenuated or weakened solutions are created on the basis of pathogenic strains with a sharply reduced ability to cause disease, but which have not lost their immunogenicity. The immune system responds to the introduction of these vaccines by forming antibodies to the infection, preventing it from developing in the future. The main part of attenuated vaccines are drugs for the prevention of rabies, influenza, Q fever, mumps, measles, rubella and various strains of adenovirus.
The second group is vaccines made from natural (divergent) strains of microorganisms that have low virulence in relation to the body, but are capable of stimulating the synthesis of protective antibodies. An example of such solutions are prophylactic smallpox vaccines made from cowpox viruses.
Features of the influenza vaccine
Influenza is a complex viral disease that annually affects hundreds of thousands of our fellow citizens, causes a huge number of complications and can even cause death in patients. The only way to prevent a dangerous infection is the timely use of a vaccine, which helps create short-term immunity, which is enough to prevent a seasonal wave of infection.
The main indications for vaccination include:
- old age (60 years and older);
- the patient has chronic diseases of the bronchopulmonary and cardiovascular systems;
- patients suffering from severe pathologies of the liver and kidneys, people with metabolic disorders, immunosuppression;
- pregnancy after 12 weeks.
Main types of anti-influenza solutions
Vaccines that protect against influenza are either live or inactivated. There are no anti-influenza toxoids. Inactivated suspensions are divided into:
- killed vaccine, which contains undestroyed but highly purified virions of the pathogen;
- split vaccine (split), consisting of destroyed viral agents;
- A subunit vaccine contains fragmented viral envelope proteins capable of inducing immune cells.
In medical practice, vaccines made from subunit solutions are often used, since they lack chicken protein and are adapted for humans. The most famous representatives of this series are the popular vaccines Agrippal and Influvac.
Immunoprophylaxis of most serious diseases 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 to the immune response. Imitation of the disease occurs in a weak form, which occurs quickly, with sparingly expressed 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 do not consist of whole microorganisms, but of individual particles of their DNA, which can cause a protective reaction in the 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 bovine rhinotracheitis, 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 mandatory 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 vaccine against rabies, 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 in 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 - the upper part of the thigh; 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 the fact that the 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 the high risk of post-vaccination complications. 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 ailments associated with the cardiovascular, respiratory system, and 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
The vaccine can only be given to a 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 that prohibit vaccination on an ongoing 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 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.
Pathological processes are divided into:
- 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 of side effects that affect 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.
Definition, purposes of application and classification.
Vaccines
- preparations from microorganisms or their metabolic products, used to create active specific acquired immunity against certain types of microorganisms or the toxins they secrete.
Rice. 1. The Act-HIB vaccine is intended for the prevention of Haemophilus influenzae IN infections.
The vaccines being developed are divided into two categories: traditional(first and second generation) and new, constructed based on biotechnology methods.
TO first generation vaccines include the classic Jenner and Pasteur vaccines, which are killed or weakened live pathogens, which are better known as corpuscular vaccines.
Under second generation vaccines we should understand drugs that are based on individual components of pathogens, that is, individual chemical compounds such as diphtheria and tetanus toxoids or highly purified polysaccharide antigens of capsular microorganisms, such as meningococci or pneumococci. These drugs are better known as chemical vaccines (molecular). Based on the number of antigens included in the vaccine, there are mono- And polyvaccines(associated), by species composition - bacterial, rickettsial, viral.
General characteristics of vaccines.
Live vaccines
are preparations containing hereditarily modified forms of microorganisms (vaccine strains) that have lost their pathogenic properties. But they retain the ability to take root and multiply in the body, causing the formation of specific immunity.
Live vaccines are obtained using two basic principles that were proposed by the founders of the doctrine of vaccination, Jenner and Pasteur.
Jenner's principle
- use of genetically close (related) strains of pathogens of infectious animal diseases. Based on this principle, vaccinia vaccine, BCG vaccine, and brucellosis vaccine were obtained.
Pasteur's principle
- obtaining vaccines from artificially weakened (attenuated) strains of pathogens. The main objective of the method is to obtain strains with hereditarily altered characteristics, i.e. low virulence and preservation of immunogenic properties. The following methods for obtaining live vaccines are used:
Inactivated (killed) vaccines
. Killed vaccines are prepared from inactivated virulent strains of bacteria and viruses that have a full set of necessary antigens. To inactivate pathogens, heat and treatment with formaldehyde, acetone, and alcohol are used, which ensure reliable inactivation and minimal damage to the structure of antigens.
Chemical vaccines
. Chemical vaccines consist of antigens obtained from microorganisms in various ways, mainly chemical methods.
The main method of obtaining chemical vaccines is to isolate protective antigens that ensure the development of reliable immunity and purify these antigens from ballast substances. Currently, molecular vaccines are produced by biosynthesis or chemical synthesis.
Anatoxins
. Toxoids are prepared from exotoxins of various types of microbes. Toxins are neutralized with formaldehyde, without losing their immunogenic properties and the ability to cause the formation of antibodies (antitoxins).
Anatoxins are released in the form single drugs(monovaccines), and as part of associated preparations intended for simultaneous vaccination against several diseases (ditrivaccines).
New generation vaccines
.
Traditional vaccines have failed to address the prevention of infectious diseases associated with pathogens that are poorly cultured or not cultured in in vivo and in vitro systems. Advances in immunology make it possible to obtain individual epitopes (antigenic determinants), which in isolated form are not immunogenic. Therefore the creation new generation vaccines requires conjugation of antigenic determinants with a carrier molecule, which can be either natural proteins or synthetic molecules (subunit, synthetic vaccines)
The achievements of genetic engineering are associated with obtaining recombinant vectorsX
vaccines- live vaccines consisting of non-pathogenic microbes, into the genome of which the genes of other (pathogenic) microorganisms are built in. In this way, the so-called yeast vaccine against hepatitis B has long been obtained, vaccines against malaria and HIV infection have been developed and are being tested, and the possibility of creating many other vaccines using this principle has been shown.
Indications for vaccinations.
There are different types of vaccinations planned and performed according to epidemic indications.
Each country uses its own national calendar of preventive vaccinations, which provides for planned mass vaccination of the population. The obligatory nature of such vaccinations is usually established by the legislation of the country.
Conditions for storage and transportation of immunobiological preparations.
Compliance with the rules of storage and transportation of immunobiological drugs is an indispensable condition. Violation of the temperature regime for storing a number of drugs is not only accompanied by a decrease in their effectiveness, but can also lead to an increase in reactogenicity, and this, in individuals with high levels of antibodies, leads to the development of immediate allergic reactions, collaptoid reactions.
Transportation and storage must be carried out in compliance with a special “cold chain” system - a smoothly functioning system that ensures optimal temperature conditions for the storage and transportation of vaccines and other immunobiological preparations at all stages of their passage from the manufacturer to the vaccinee. Optimal for storage and transportation of most vaccines and other immunobiological preparations is temperature within 2-8°С.
Destruction of unused medical immunobiological preparations.
Ampules and other containers containing unused remains of inactivated bacterial and viral vaccines, as well as live measles, mumps and rubella vaccines, toxoids, human immunoglobulins, heterologous sera, as well as the instruments that were used for their administration, are not subject to any special processing .
Ampoules and other containers containing unused remains of other live bacterial and viral vaccines, as well as the instruments used for their administration, must be boiled for 60 minutes (anthrax vaccine 2 hours), or treated with a 3-5% chloramine solution for 1 hour, or 6% hydrogen peroxide solution (shelf life no more than 7 days) for 1 hour, or autoclave.
All unused batches of drugs that have expired, as well as those that cannot be used for other reasons, should be sent for destruction to the district (city) center of state sanitary and epidemiological supervision.
Checking the physical properties of immunobiological preparations before vaccination.
Check the label or marking of the drug on the box, ampoule (vial), read the information about the drug, expiration date, check the integrity of the ampoules, and compliance with the appearance requirements. If there is no label, expiration date, ampoules are not sealed, or changes in appearance (color, presence of flakes, foreign inclusions, etc.), the drugs cannot be replaced.
Rice. 2. Before vaccination, immunobiological preparations must be checked for compliance with their physical properties.
Carrying out vaccinations.
Vaccinations must be carried out in a room specially designated for this purpose (vaccination rooms in children's clinics, medical rooms in kindergartens and schools, etc.). If it is impossible to allocate a separate room for routine vaccinations, a strictly fixed time should be determined during which other medical procedures should not be carried out in it. Vaccinations in dressing rooms are strictly prohibited. Vaccinations must be carried out under aseptic conditions.
Before vaccinations, it is necessary to check the health status of the person being vaccinated: questioning, examination, thermometry (not allowed for sore throat, respiratory tract infections, pustular lesions of the skin and mucous membranes, regardless of location).
Rice. 3. Vaccinations are carried out in special rooms under aseptic conditions.
Vaccination records.
For children - a development history and a map of preventive vaccinations. For adults - a vaccination log. From the moment of the first vaccination, each person is issued a “Certificate of Preventive Vaccinations,” which is an important document and is kept by its owner for life.
Information about the implementation of vaccinations, as well as severe reactions and complications, is sent to the center of state sanitary and epidemiological supervision and to the department of post-vaccination complications of GISC (State Institute for Standardization and Control of Medical Biological Preparations).
Reactions to vaccination drugs.
Vaccines introduced into the body usually cause are common And local reactions accompanying the vaccination process and the formation of post-vaccination immunity. The severity of the reaction depends on the properties of the drug and the individual characteristics of the organism.
Table 1.
Characteristics of local reactions
vaccine requirements.
Safety is the most important property of a vaccine; it is carefully studied and monitored in
process of production and use of vaccines. The vaccine is safe if administered to people
does not cause the development of serious complications and diseases;
Protectiveness - the ability to induce specific defense of the body against
a certain infectious disease;
Duration of preservation of protection;
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;
Easy to administer.
Types of vaccines:
Live vaccines are made from weakened strains of a microorganism with genetically fixed avirulence. The vaccine strain, after administration, multiplies in the body of the vaccinated person and causes a vaccine infectious process. In the majority of vaccinated people, the vaccine infection occurs without pronounced clinical symptoms and leads, as a rule, to the formation of stable immunity. Examples of live vaccines include vaccines for the prevention of polio (Sabin live vaccine), tuberculosis (BCG), mumps, plague, anthrax, and tularemia. Live vaccines are available in lyophilized (powdered) form.
form (except polio). Killed vaccines are bacteria or viruses that have been inactivated by chemical (formalin, alcohol, phenol) or physical (heat, ultraviolet irradiation) effects. Examples of inactivated vaccines are: pertussis (as a component of DTP), leptospirosis, whole virion influenza, vaccine against tick-borne encephalitis, against inactivated polio vaccine (Salk vaccine).
Chemical vaccines are obtained by mechanical or chemical destruction of microorganisms and the release of protective antigens, i.e., those that cause the formation of protective immune reactions. For example, a vaccine against typhoid fever, a vaccine against meningococcal infection.
Anatoxins. These drugs are bacterial toxins that are rendered harmless
exposure to formaldehyde at elevated temperatures (400) for 30 days, followed by purification and concentration. Toxoids are sorbed on various mineral adsorbents, for example, 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 the adjuvant
by the action of the sorbent, which causes local inflammation, enhancing the plasmacytic reaction in the regional lymph nodes. Toxoids are used to prevent tetanus, diphtheria, and staphylococcal infections.
Synthetic vaccines are artificially created antigenic determinants of microorganisms.
Associated vaccines include drugs from previous groups and against several infections. Example: DTP - consists of diphtheria and tetanus toxoids adsorbed on aluminum hydroxide and killed pertussis vaccine.
Vaccines obtained using genetic engineering methods. 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 vaccine against viral hepatitis B and the vaccine against rotavirus infection.
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 integrate the genes of the microorganism responsible for the synthesis of microbial protein into the human genome. In this case, human cells stop producing this foreign protein, and the immune system begins to produce antibodies to it. These antibodies will neutralize the pathogen if it enters the body.
