A vaccine (inactivated) is a medicine consisting of viral particles grown in culture that have been destroyed by a heat treatment method and the action of a cellular poison (formaldehyde). Such viruses are cultured in a laboratory environment to reduce antigenicity and are considered non-infectious (incapable of causing disease). Killed vaccines are much less productive than live vaccines, but when administered a second time, they form quite strong immunity.
How vaccines are made
To create them, as a rule, epizootic harmful viruses are used, which undergo gentle purification (inactivation), leading to an irreversible loss of the virus's susceptibility to reproduce (multiply), but at the same time, its immunogenic and antigenic features are preserved. Therefore, the nucleic acid (viral genome) that the vaccine contains (inactivated) must be killed - this is the environment where it reproduces well.
Polysaccharides, proteins and glycoproteins of the virus should also not change, because the protective reactiondepends on the substances of the capsid of the virus. As a result, it loses the ability to reproduce and infect, but retains susceptibility to the activation of characteristic factors of immunity in animals and humans.
Drug Manufacturing Technology
The creation of inactivated vaccines begins with the selection of a production strain of the virus, cultivation, and its accumulation in a sensitive biological construct (cell cultures, animals, bird embryos). Then the virus-containing raw material is purified and combined in various ways (ultra-, centrifugation, filtration, and others).
The vaccine (inactivated) is also the result of saturation, cleansing of viral agents. This process is very important, because the destroyed virus does not spread in the body, and in order to obtain a strong protective reaction, a large amount of viral material must be injected. Suspensions of the virus must be processed from ballast substances (lipids, remnants of cellular structures, non-viral proteins), which carry out an extra load on the body's immunity and significantly reduce the intensity and specificity of protective reactions.
The virus-containing suspension acquired after saturation and purification is subjected to inactivation. In the case of particularly aggressive viruses, inactivation precedes the treatment action. In this case, it is necessary to take into account that ballast substances interfere with the inactivation process.
When an influenza (inactivated) vaccine is made, for example, a very important pointis the choice of an inactivator, as well as an ideal inactivation medium that makes it possible to completely deprive the virus of infectivity while preserving antigenicity to the greatest extent. But the design of inactivating reactions is poorly understood, and their use is often experimental.
Properties of inactivated vaccines
For the prevention of viral illnesses, inactivated vaccines are well used, which have a number of advantages over live ones. An important requirement for their productivity is the quality and quantity of the viral antigen, the selection of an inactivator and suitable conditions for inactivation. The term "inactivated" refers to the vital activity of the viruses included in the drug solution.
Live and inactivated vaccines are mostly prepared from virulent viruses, destroying toxicity by physical and chemical means while maintaining immunogenicity. These drugs must be harmless and have a lot of viral antigen in order to provoke a defensive reaction and the production of antibodies. The usual course of initial vaccination is 2-3 injections. In the future, boostering may be needed to support immunity.
What disadvantages do they have
Inactivated vaccines are more stable and safer. They are used mainly for the purpose of prevention in industries and hazardous areas. However, such drugs have some disadvantages:
- the technology of their production is very complex, and this is due to the need to obtaina significant number of virus-containing raw materials, saturation, antigen purification, inactivation of the viral genome, as well as the inclusion of adjuvants in the structure of the vaccine;
- may sometimes cause allergic reactions as a result of secondary vaccination;
- you need to inject more than once and in large dosages;
- vaccine (inactivated) is still a weak stimulant of the body's defense, in this regard, the resistance of the digestive tract and mucous membranes of the upper respiratory passages is less pronounced than after using live vaccines;
- they can only be used parenterally;
- drugs induce insufficiently long and intense immunity than with live vaccinations.
What is polio and how does it manifest?
Polio is an acute viral infection that affects the nervous system (the colorless substance of the spinal cord). Flaccid paralysis begins to appear, especially of the lower extremities. More severe cases of damage to the spinal cord lead to respiratory arrest. And here the already inactivated polio vaccine may not help.
Clinically, such a disease may be accompanied by an increase in temperature, muscle and headaches with further formation of immobility. The disease is transmitted from one person to another when sneezing, talking, through water, dirty objects, and food. Sick people are considered the cause of infection. The infection spreads instantly, but the assumption that polio has set in appears when it is already fixedfirst case of paralysis.
The time of incubation of the disease from the onset of infection to the onset of the first signs lasts 1-2 weeks, it can also be from 4 to 40 days. Viruses enter the body through the mucous membranes of the intestines or nasopharynx, are bred there, and then enter the bloodstream, reach the nerve cells of the spinal cord and brain and destroy them. So, paralysis appears.
Vaccination against polio for children
It must be taken into account that this disease is a viral infection and there is no special treatment that affects just these viruses. The only effective medicine to prevent sickness is vaccination.
Two tools are used to prevent polio:
- an inactivated polio vaccine (IPV), which contains dead wild-type viruses of the disease and is given by injection;
- oral live polio vaccine (OPV) with weak modified live viruses (liquid dripped into the mouth).
These drugs contain 3 types of polio viruses, that is, they protect against all available variants of this infection. However, polio vaccines are not yet produced in Russia, but there is a foreign medicine, Imovax Polio, which is well applicable for vaccination. In addition, an inactivated polio vaccine is part of Tetracoc (a compound drug for the prevention of whooping cough, diphtheria and tetanus). Both of these means are used without violating the laws of trade and at the request of the parents. These vaccines can be given at the same time asimmunoglobulin.
Inactivated Polio Vaccine Instructions
A variety of such a medicine is produced in liquid form, the packaging is in 0.5 ml dosing syringes. The method of administration is an injection. Infants under 18 months of age are injected subcutaneously into the subscapularis, shoulder or thigh intramuscularly. Older children - only in the shoulder area. There are no contraindications for time and drinking, no food.
Effect on the body
After the introduction of the polio vaccine, 5-8% of those vaccinated may experience local reactions (this is not a problem of vaccination) in the form of redness and swelling, no more than 10 cm in diameter. Only in 1-5% of cases are general vaccine reactions detected as a temporary slight rise in temperature, agitation of the child 1-2 days after vaccination.
Imovax Polio
Such a tool is successfully used in Russia. The vaccine is given even to exhausted children who have ailments of the gastrointestinal tract. In addition, the polio vaccine (inactivated) is divided into 4 injection stages: at 3, 4 and 6 months. Revaccination at 18.
A vaccinated baby is not considered contagious to others. However, it is still recommended to minimize his presence in crowded places for a week after vaccination, because a child weakened by the virus can become infected with another infection. The injection is given in the thigh or shoulder. Redness of the areathe introduction of "Imovax" is the norm, and the temperature due to vaccination can reach 39 degrees and above.
Inactivated polio vaccine: complications
Some problems have been identified that appear after vaccination with complex medicines Infanrix Hexa, Pentaxim, Infanrix IPV, Tetrakok:
- otitis media;
- weakness;
- toothache and stomatitis;
- enlarged lymph nodes;
- anxiety;
- itchy skin rash;
- anaphylactic shock;
- pain and tightness in the injection area;
- sleep disorder;
- diseases of the upper respiratory tract;
- fever and spasms at its stage;
- Quincke's edema;
- nausea;
- diarrhea;
- vomit;
- atypical crying;
- increased body temperature.
Complications often occur and the child's defense system is stressed when polio and DTP are given. The reaction can be detected both from drops and from pertussis-tetanus.
Contraindications
The polio vaccine is not a cultured (inactivated) rabies vaccine that is made against rabies in animals. It is primarily a medicine that protects the child from further paralysis, and possibly death. Right before vaccination, you need to visit a pediatrician to take directions from him for a general urine and blood test, then take them to a medical clinic. Based on the analyzes andAfter examining the baby, the doctor will tell you if it is possible for him to produce the vaccine at the moment. Vaccination restrictions include:
- Exhaustion.
- Severe infection or exacerbation of chronic.
- Teething.
- Immunodeficiency (low white blood cell count).
- Hypersensitivity to ingredients.
- Acute inflammatory reaction of any part of the body or its exacerbation.
- Neoplasms of hematopoietic and lymphoid tissue.
After suffering a serious illness or its aggravation, a child can be vaccinated no earlier than 14 days after the cure with normal blood counts. The same contraindications exist in cases where the child is he althy, but one of the household is infected with an infectious disease. As a result of the introduction of the medicine (and which vaccines are inactivated - everyone probably already knows), the baby needs to stop introducing the next complementary foods for a week.
You need to be careful
People who have not been vaccinated against polio (regardless of age), while suffering from immunodeficiency, can become infected from vaccinated children and become ill with vaccine-associated polio (VAP). There are cases when parents who have AIDS or HIV were infected from a vaccinated child, as well as relatives with an initial immunodeficiency or those who take medications that destroy the body's defense system (in the treatment of oncological ailments).
A vaccine against a disease like polio, if produced correctly and by all standards, will help a fragile babycounteract dangerous and serious illness. And, consequently, it will make the child stronger, strengthen his body and protect parents from most of the difficulties, experiences that, as a rule, the family of a very sick child has to experience.
