Vaccines- immunobiological preparations intended for active immunoprophylaxis, that is, to create active specific immunity of the body to a specific pathogen. Vaccination recognized by WHO as an ideal method for the prevention of human infectious diseases. High efficiency, simplicity, and the possibility of wide coverage of vaccinated individuals with the aim of mass prevention of the disease have brought active immunoprophylaxis to the level of government priorities in most countries of the world. The set of vaccination measures includes the selection of persons to be vaccinated, the choice of a vaccine drug and the determination of a scheme for its use, as well as (if necessary) monitoring of effectiveness, relieving possible pathological reactions and complications. The following are used as Ags in vaccine preparations:

Whole microbial bodies (live or killed);
individual Ags of microorganisms (most often protective Ags);
microorganism toxins;
artificially created Ag microorganisms;
Ag obtained by genetic engineering methods.

Most vaccines divided into living, inactivated (killed, non-living), molecular (toxoids), genetically engineered and chemical; according to the presence of a complete or incomplete set of Ags - into corpuscular and component, and according to the ability to develop immunity to one or more pathogens - into mono- and associated.

Live vaccines

Live vaccines- preparations from attenuated (weakened) or genetically modified pathogenic microorganisms, as well as closely related microbes that can induce immunity to the pathogenic species (in the latter case we are talking about so-called divergent vaccines). Because everything live vaccines contain microbial bodies, they are classified as part of the group of corpuscular vaccine preparations.

Immunization with live vaccine leads to the development of the vaccine process, which occurs in the majority of vaccinated people without visible clinical manifestations. The main advantage of live vaccines is the completely preserved set of pathogen Ags, which ensures the development of long-term immunity even after a single immunization. Live vaccines also have a number of disadvantages. The most typical is the risk of developing a manifest infection as a result of decreased attenuation of the vaccine strain. Similar phenomena are more typical for antiviral vaccines (for example, live polio vaccine in rare cases can cause polio, including the development of spinal cord damage and paralysis).

Weakened (attenuated) vaccines

Weakened ( attenuated) vaccines made from microorganisms with reduced pathogenicity, but pronounced immunogenicity. The introduction of a vaccine strain into the body imitates an infectious process: the microorganism multiplies, causing the development of immune reactions. The most well-known vaccines are for the prevention of anthrax, brucellosis, Q fever, and typhoid fever. However, most live vaccines- antiviral. The best known are the yellow fever vaccine, the Sabin anti-poliomyelitis vaccine, and vaccines against influenza, measles, rubella, mumps, and adenoviral infections.

Divergent vaccines

As vaccine strains are used by microorganisms that are closely related to pathogens of infectious diseases. The Ags of such microorganisms induce an immune response cross-directed to the Ag of the pathogen. The most well-known and long-used vaccine is against smallpox (from the cowpox virus) and BCG for the prevention of tuberculosis (from mycobacterium bovine tuberculosis).

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COMPILERS: Doctor of Medicine, Prof. M.A. Gorbunov, Doctor of Medical Sciences, Prof. N.F. Nikityuk, Ph.D. G.A. Elshina, Ph.D. V.N. Ikoev, Ph.D. N.I. Lonskaya, b. n. K.M. Mefed, M.V. Solovyova, Federal State Budgetary Institution "NTsESMP" Ministry of Health and Social Development of Russia, Center for Expertise and Control of ILP

Vaccines- these are drugs obtained from live attenuated strains or killed cultures of microorganisms and their antigens, intended to create an active immune response in the body of vaccinated people and animals.

Among the various groups of medical biological preparations used for immunoprophylaxis and immunotherapy of infectious diseases, vaccines are the most effective means of preventing infectious diseases. The main active principle of each vaccine is an immunogen, which is similar in structure to the components of the pathogen responsible for the production of immunity.

Depending on the nature of the immunogen, vaccines are divided into:

• alive;

• killed (inactivated);

• split (split vaccines);

• subunit (chemical) vaccines;

• toxoids;

• recombinant;

• conjugated;

• virosomal;

• artificially adjuvanted vaccines;

• combined (associated polyvaccines).

Live vaccines

Live vaccines contain weakened living microorganisms (bacteria, viruses, rickettsia), created on the basis of apathogenic pathogens, attenuated under artificial or natural conditions, by inactivating genes or due to their mutations. Live vaccines create stable and long-lasting immunity, the intensity of which is close to post-infectious immunity; however, to develop immunity, as a rule, a single administration of the drug is sufficient. The vaccine infectious process lasts several weeks, is not accompanied by a clinical picture of the disease and leads to the formation of specific immunity.

Killed (inactivated) vaccines

Killed vaccines are prepared from inactivated virulent strains of bacteria and viruses and contain a killed whole microorganism, or components of the cell wall and other parts of the pathogen, which have a full set of necessary antigens. To inactivate pathogens, physical (temperature, radiation, UV rays) or chemical (alcohol, acetone, formaldehyde) methods are used that ensure minimal damage to the structure of antigens. These vaccines have lower immunological effectiveness compared to live vaccines, so vaccination is carried out mainly in 2 or 3 doses and requires revaccination, which forms a fairly stable immunity, protecting those vaccinated from the disease or reducing its severity.

Split (split vaccines)

Vaccines contain destroyed inactivated virions, while retaining all viral proteins (surface and internal). Due to high purification from viral lipids and proteins of the chicken embryo, the cultivation substrate, split vaccines have low reactogenicity. A high degree of specific safety and sufficient immunogenicity allow their use among children from 6 months of age and pregnant women.

Subunit (chemical) vaccines

Subunit vaccines consist of individual antigens of a microorganism that can provide a reliable immune response in the vaccinated person. To obtain protective antigens, various chemical methods are mainly used, followed by purification of the resulting material from ballast substances. The use of adjuvants enhances the effectiveness of vaccines. subunit (chemical) vaccines have weak reactogenicity, can be administered in large doses and repeatedly, and can also be used in various associations aimed simultaneously against a number of infections.

Anatoxins

Anatoxins are prepared from microbial exotoxins that have lost their toxicity as a result of neutralization by formaldehyde when heated, but have retained their specific antigenic properties and the ability to induce the formation of antibodies (antitoxins). The toxoid, purified from ballast substances and concentrated, is sorbed on aluminum hydroxide. Toxoids form antitoxic immunity, which is weaker than post-infectious immunity.

Recombinant vaccines (vector)

Recombinant vaccines are obtained by cloning genes that ensure the synthesis of the necessary antigens, introducing these genes into the vector and into producer cells (viruses, bacteria, fungi, etc.), then cultivating the cells in vitro, separating the antigen and purifying it. New technology has opened up broad prospects for creating vaccines. Recombinant vaccines are safe, quite effective, highly effective technology is used to obtain them, they can be used to develop complex vaccines that create immunity against several infections simultaneously.

Conjugate vaccines

Vaccines are conjugates of a polysaccharide obtained from infectious agents and a protein carrier (diphtheria or tetanus toxoid). Antigen polysaccharides have weak immunogenicity and a weak ability to form immunological memory. the binding of polysaccharides to a protein carrier that is well recognized by the immune system sharply enhances the immunogenic properties of the conjugate and causes protective immunity.

Virosomal vaccines

Virosomal vaccines contain an inactivated virosomal complex associated with highly purified protective antigens. Virosomes function as antigen carriers and adjuvant, enhancing the immune response, capable of inducing both humoral and cellular immunity.

Vaccines with artificial adjuvant

The principle of creating such vaccines is to use natural antigens of infectious disease pathogens and synthetic carriers. One of the variants of such vaccines consists of a protein antigen of the virus and an artificial stimulant (for example, polyoxidonium), which has pronounced adjuvant (increasing the immunogenicity of antigens) properties.

Combined vaccines (associated polyvaccines)

These vaccines are a mixture of strains of different types of pathogens or their antigens to prevent two or more infections. When developing combination vaccines, the compatibility of not only the antigenic components, but also their various additives (adjuvants, preservatives, stabilizers, etc.) is taken into account. These are different types of vaccines containing several components. Adverse reactions of the body to associated vaccines occur, as a rule, somewhat more often than to mono-vaccines, but they make it possible to protect those vaccinated in a short time from several infectious diseases.

An urgent task of modern vaccinology is the constant improvement of vaccine preparations, approaches to their use, development of regimens, dosages, methods and timing of administration among various age groups.

Features of vaccine production technology, as well as the mechanism of their action in the formation of immunity, must be taken into account when organizing and conducting all stages of clinical trials.

Before the start of clinical trials, the choice of territories and populations for conducting the planned research should be clearly justified. For this purpose, it is necessary to conduct a retrospective epidemiological analysis of an infectious disease in a certain area among the population included in the clinical trial protocol. Based on the results of epidemiological analysis, groups of volunteers are selected according to age, gender, social characteristics, including territorial and seasonal fluctuations in incidence, which is extremely necessary when planning clinical trials and determining the safety and effectiveness of various types of vaccines.

Read also

• General provisions for conducting clinical trials of vaccines
• Clinical studies of inactivated influenza vaccines
• Features of clinical trials of vaccines against HIV/AIDS
• Features of clinical trials of vaccines against particularly dangerous infections
• Features of clinical trials of vaccines against measles, mumps and rubella

It is very good that now every mother has the opportunity to choose, from the gynecologist who is in charge of her pregnancy, the maternity hospital where her little miracle will be born, and to the pediatrician who accompanies her baby almost from birth to adulthood. Also, a mother can choose a vaccine to vaccinate her baby according to. True, for the most part, she will have to rely on the doctor’s advice, taking into account the child’s health condition. But it’s still worth knowing what this or that vaccination is for your mother.

There are several types of vaccines. Some contain live bacteria (yes, exactly live bacteria, however, they are already “neutralized”), others are chemical, but no less effective. Let's try to figure it out.

Live vaccines

In medical circles, live vaccines are called attenuated vaccines. But you shouldn’t be afraid of them, because, as we wrote above, microorganisms are weakened. The introduction of live vaccines allows the body to develop very strong immunity to diseases. These include vaccinations against measles, rubella, mumps (mumps), polio (in droplets), tuberculosis (BCG). Their disadvantage is that after vaccination the child is a carrier of the virus and spreads the infection around him for some time, which can pose a danger to unaccustomed people. And this has been proven by researchers. Don’t be surprised if, after vaccination with such a vaccine, the doctor may advise you not to visit childcare centers, playgrounds, or crowded places for a couple of days.

Inactivated vaccines

Inactivated vaccinations have several subtypes.

• A corpuscular vaccine is a drug containing killed pathogens. These are vaccinations against whooping cough, influenza, rabies, tetanus, diphtheria, Haemophilus influenzae, viral hepatitis and, again, polio (in injections). The advantage of such vaccines is their easy tolerability. And there are no special requirements for their storage (the main thing is not to freeze). At the same time, the immunity that is produced by the body after its administration is much weaker than after the introduction of a live one.

• Chemical vaccines are created from virus antigens extracted from the microorganism's cell itself. The advantage of such vaccinations is that they are well tolerated by the child’s body and are easy to calculate the required dose for children of different weights or ages. Such vaccinations include vaccines against tetanus, diphtheria, typhoid fever,.
• A recombinant vaccine is produced using genetic engineering methods using special technologies. A gene responsible for the production of protective antigens is isolated from a harmful microorganism and inserted into a harmless microorganism (for example, chicken protein or yeast). As the donor cell develops, it accumulates the desired antigen. These are vaccinations against herpes simplex, rotavirus infection, hepatitis B, and human papilloma. Scientists claim that such a vaccine is practically harmless to the body.

With the invention of vaccines, we have the opportunity to protect babies from serious diseases that can cause complications. Among them are polio, whooping cough, and tuberculosis. To understand all the intricacies of vaccination and the timing of vaccinations, we suggest you take a look at the vaccination primer.

4 reasons why children should be vaccinated

• Babies are very vulnerable, which means they need protection, especially when it comes to infectious diseases that can lead to serious consequences. The possibilities of modern medicine are not limitless. For example, the more than fifty-year history of the existence of antibiotics has proven that they do not always help cure diseases, and for diseases caused by viruses, they do not help at all.
• The vaccinations given to our children are not at all the same as those given to us! Vaccinology (the science of vaccinations) does not stand still and has achieved a lot over the past 15 years. For example, most of the vaccines we have known since childhood are now lightweight, that is, they are free of components that can cause unwanted reactions.
• The modern vaccination calendar is much wider than before, and combining different vaccines into one simplifies the procedure.
• New vaccines are emerging that help protect babies from many serious diseases that could not be controlled before. For example, a vaccine was recently invented against Haemophilus influenzae type B, which causes meningitis.

Allergy

Children with allergies also need to be vaccinated: they are susceptible to many diseases, especially complications after them, even to a greater extent than other children. There are practically no contraindications for vaccinations now. There is only one “but” - it concerns live vaccines with viruses, for example the measles virus, which is grown on eggs (chicken or quail). This vaccine cannot be administered to babies who are allergic to eggs (by the way, it is very rare among infants).

There is no need to worry that your baby will develop allergies due to the vaccine. If he has a predisposition, the drug can only manifest it, and then an allergic reaction will occur not to the vaccine itself, but to some of its components or another allergen, which can be any new product. Whether a small allergic person needs a vaccination and when it should be done is decided by the doctor (for example, at the time of exacerbation of atopic dermatitis, it will be postponed). If the doctor deems it necessary, he will prescribe the baby a medicine that must be taken after the vaccination to avoid an undesirable reaction.

This vaccination is very important for children because every year there are outbreaks of tuberculosis around the world. is mandatory (unless there are medical contraindications) and protects the child from severe forms of pulmonary tuberculosis and tuberculous meningitis. The first time children are vaccinated is still in the maternity hospital, and then shortly before entering a nursery, kindergarten or school. Before repeating it, the doctor will do a special test. It's called a reaction. The sample contains some tuberculin, a component of the microbe that causes tuberculosis. It is injected into the skin, and if redness appears around the injection site, it means there is immunity against tuberculosis, and if the desired reaction does not follow, the vaccination should be repeated.

Hepatitis A

In Russia, this vaccination is given to children if necessary, for example, if you are going on a trip with your whole family.

If the mother of a newborn is a carrier of the virus, there is a risk that the baby will become infected with hepatitis during childbirth. To prevent this from happening, he is vaccinated within 72 hours after birth.

Fortunately, such cases are rare. The vaccination calendar prescribes vaccinating babies three times: at 4, 5 and 12 months.