A vaccine (inactivated) is a medicine consisting of viral particles grown in culture that have been destroyed by the heat treatment and the action of cell poison (formaldehyde). Such viruses are cultured in a laboratory environment to reduce antigenicity and are considered non-infectious (unable to provoke a disease). Killed vaccines are characterized by much lower productivity compared to live ones, but upon secondary administration they form a rather strong immunity.
How to get the vaccines
To create them, as a rule, they use epizootic malicious viruses that undergo gentle cleaning (inactivation), which leads to an irreversible loss of susceptibility of the virus 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 multiplies well.
Also, the polysaccharides, proteins and glycoproteins of the virus should not be changed, because the protective reaction depends on the capsid substances of the virus. As a result, it loses its ability to reproduce and become infected, however, it retains susceptibility to activation of characteristic immunity factors in animals and humans.
Manufacturing Technology
The creation of inactivated vaccines begins with the selection of a production strain of the virus, cultivation, as well as its accumulation in a sensitive biological construct (cell cultures, animals, bird embryos). Then the virus-containing raw materials are purified and combined in various ways (ultra-, centrifugation, filtration and others).
A vaccine (inactivated) is also the result of saturation, purification of viral agents. This process is a very important point, because the destroyed virus does not spread in the body, and to obtain a strong protective reaction, you need to enter a large amount of viral raw material. Suspensions of the virus should be processed from ballast substances (lipids, residues of cellular structures, non-viral proteins), which carry an extra load on the body's immunity and significantly reduce the intensity and nature of the protective reactions.
Acquired after saturation and purification, the virus-containing suspension is inactivated. In a situation with particularly aggressive viruses, inactivation precedes the action of the treatment. It should be borne in mind that ballast substances interfere with the inactivation process.
When an influenza (inactivated) vaccine is made, for example, the choice of an inactivator, as well as the ideal inactivation medium, which makes it possible to completely deprive the virus of infectivity with the greatest antigenicity saving, is very important. But the design of inactivating reactions is poorly studied, and their use is often experimental.
Properties of Inactivated Vaccines
For the prevention of viral ailments, inactivated vaccines are well used, which have a number of advantages compared to live ones. An important requirement for their productivity is the quality and quantity of the viral antigen, the selection of the inactivator and the appropriate inactivation conditions. The term "inactivated" refers to the vital activity of viruses entering the drug solution.
Live and inactivated vaccines are mostly harvested from virulent viruses, eliminating toxicity physically and chemically while maintaining immunogenicity. These drugs must be harmless and have a lot of viral antigen in order to provoke a protective reaction and the production of antibodies. The usual initial vaccination course is 2–3 injections. Boosterization may be needed in the future to support immunity.
What are their disadvantages?
Inactivated vaccines are more consistent qualities, in addition, they are safe. They are used mainly for the purpose of prevention in industries and hazardous areas. However, such drugs differ in some disadvantages:
- their production technology is very complex, and this is due to the need to obtain a 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;
- sometimes they can cause allergic reactions as a result of secondary vaccination;
- you need to do injections more than once and in large doses;
- a vaccine (inactivated) is still a weak stimulant to protect the body, in this regard, resistance of the digestive tract and mucous membranes of the upper respiratory passages is less pronounced than after using live vaccines;
- they can be used only parenterally;
- drugs do not induce a sufficiently long and intense immunity than with live vaccinations.
What is poliomyelitis and how does it manifest?
Poliomyelitis is an acute viral infection that affects the nervous system (a colorless substance of the spinal cord). Flaccid paralysis, especially of the lower limbs, begins to appear. More severe cases of damage to the spinal cord lead to respiratory arrest. And here already inactivated polio vaccine may not help.
Clinically, such a disease can be accompanied by an increase in temperature, muscle and headaches, with the further formation of immobility. The disease is transmitted from one person to another by sneezing, talking, through water, dirty objects, as well as food. The cause of infection is considered sick people. The infection spreads instantly, but the assumption that poliomyelitis has occurred appears when the first case of paralysis is already recorded.
The time of incubation of the disease from the onset of infection to the onset of the first signs lasts 1-2 weeks, may also be from 4 to 40 days. Viruses enter the body through the mucous membranes of the intestines or nasopharynx, get divorced there, and then enter the bloodstream, reach the nerve cells of the spinal cord, brain and destroy them. So, paralysis appears.
Polio vaccination for children
It must be borne in mind that this disease is a viral infection and there is no special treatment that affects these viruses. The only effective medicine for preventing malaise is vaccination.
To prevent polio, two agents are used:
- inactivated polio vaccine (IPV), which contains dead wild viruses of the disease and is administered by injection;
- oral live polio vaccine (OPV), which has weak modified live viruses (fluid drips into the mouth).
These drugs include 3 types of polio viruses, that is, they protect against all available variants of this infection. However, so far no poliomyelitis vaccines are being manufactured 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 the Tetrakok tool (a medication for the prevention of pertussis, diphtheria and tetanus). Both of these funds are used without violating the laws of trade and at the request of the parents. Such vaccines can be administered at the same time with immunoglobulin.
Inactivated polio vaccine: instruction
A kind of such a medicine is made in liquid form, the packaging is in 0.5 ml syringes. The route of administration is injection. Infants under 18 months of age are injected subcutaneously into the subscapularis, shoulder or thigh intramuscularly. Older children - only in the shoulder region. There are no contraindications for time and drinking, no food.
Effects on the body
After administration of the polio vaccine , 5-8% of vaccinees may experience local reactions (this is not a vaccination problem) in the form of redness and swelling, not more than 10 cm in diameter. Only in 1-5% of cases, general vaccine reactions are detected as a temporary slight temperature increase, the child's excitement for 1-2 days after vaccination.
The drug "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. At 18 there is a booster shot.
A vaccinated baby is not considered contagious to others. However, it is recommended to minimize its 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 done in the thigh or shoulder. Redness of the administration area of Imovax is normal, 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 the complex medicines Infanrix Hexa, Pentaxim, Infanrix IPV, Tetracock:
- otitis;
- weakness;
- toothache and stomatitis;
- enlarged lymph nodes;
- anxiety;
- itchy skin rash;
- anaphylactic shock;
- pain and compaction in the injection zone;
- sleep disorder;
- upper respiratory tract diseases;
- fever and cramping at its stage;
- Quincke's edema;
- nausea;
- diarrhea;
- vomiting
- atypical crying;
- fever.
Often complications appear, and the load on the child’s protective system increases when polio and DTP are vaccinated. The reaction can be detected both from drops and from pertussis-tetanus agents.
Contraindications
The polio vaccine is not a rabies culture (inactivated) vaccine that is given to rabies animals. This is primarily a medicine that protects the child from further paralysis, and possibly from death. Right before vaccination, you need to visit a pediatrician to take directions from him for a general analysis of urine and blood, then pass them to a medical clinic. Based on the tests and examination of the baby, the doctor will tell you if he can be vaccinated at the moment. The vaccination restrictions include:
- Exhaustion.
- Severe infection or exacerbation of chronic.
- Teething.
- Immunodeficiency (a decrease in the number of white blood cells).
- Hypersensitivity to the ingredients.
- An acute inflammatory reaction of any part of the body or its exacerbation.
- Neoplasms of the hematopoietic and lymphoid tissue.
After suffering a serious illness or its aggravation, a child can be vaccinated no earlier than 14 days after treatment at normal blood counts. The same contraindications exist in cases when the child is healthy, but one of the household is infected with an infectious disease. As a result of the introduction of the drug (and which vaccines are inactivated - everyone probably already knows), the baby needs to stop the next complementary feeding for a week.
Care must be taken
People who have not been vaccinated against poliomyelitis (regardless of age) and who are immunodeficient can become infected from vaccinated children and become ill with vaccine-associated polio (VAP). There are cases when parents who are sick with AIDS or HIV, as well as relatives with the initial immunodeficiency or those who take medications that destroy the body's defense system (during the treatment of oncological ailments) were infected from the vaccinated child.
A vaccine against a disease such as polio, if it is produced correctly and by all standards, will help a fragile baby to counteract a dangerous and serious illness. And, therefore, it will make the child stronger, strengthen his body and protect his parents from most difficulties, experiences that, as a rule, a family of a very sick child has to experience.