Poliomyelitis is an acute infectious pathology in which the virus infects the gray matter of the spinal cord and medulla oblongata. Its consequences are paralysis leading to lifelong disability. It is believed that in Russia, the countries of Europe and America, this dangerous disease was defeated, and polio vaccines helped to do this . The schedule in Russia provides for their implementation in the first months of a childβs life.
Polio
Poliomyelitis is an acute infection that is caused by a virus that has three serotypes. The source of infection is sick people and virus carriers. The disease is transmitted by fecal-oral and drip routes. That is, you can get infected by contact, through water, dishes, products that have been exposed to the virus. In the external environment, it is stable enough, which can provoke epidemics. Most affected are children from 3 months to 5 years. In typical forms of polio, the virus infects the motor nuclei of the brain stem and spinal cord. Clinically, this is expressed either by meningitis, or the development of paralysis, paresis, muscle atrophy. Also, the disease can be asymptomatic or in an erased form. A person who has suffered polio retains lifelong immunity. The vaccination schedule allows you to develop artificial immunity to this infection from childhood. But you need to keep in mind that in the absence of vaccination, even after having polio, a person can again become infected with it, but another type of virus will be the causative agent.
Types of vaccines
To date, two types of vaccines have been developed. Distinguish between live oral polio vaccine (OPV) and inactivated polio vaccine (IPV). In Russia, at the state level, all measures are being taken to reduce the incidence rate in the population, and to create immunity to such a pathology as poliomyelitis. Vaccination (the vaccination schedule will be presented below) can be done by both OPV and IPV. Both vaccine variants contain all three types of virus that causes the disease. In our country, both live and inactivated vaccines are allowed for use. In addition, the latter is part of the combined drug "Tetrakok", which is used while vaccinating against diseases such as diphtheria, tetanus, pertussis, poliomyelitis. The schedule of vaccinations from the latter allows two schemes. In one of them, IPV is used for vaccination, and for revaccination of OPV, the other involves the introduction of only IPV.
Oral vaccine
OPV was developed in 1955 by the American virologist A. Seibin. It includes a living, but attenuated virus. Externally, the vaccine is a liquid colored red with a bitter taste. The vaccine is administered through the mouth by instillation, depending on its concentration, from 2 to 4 drops. Polio vaccination schedule for children up to one year recommends instilling the vaccine on the root of the tongue to avoid regurgitation. In older people, it is instilled onto the palatine tonsil. After the procedure, food and drink should be excluded for an hour. If the child still burps, the same dose is reintroduced.
Through the lymphoid tissue of the pharynx, the weakened virus enters the intestines, where it begins to multiply, in response to which the immune system begins to produce antibodies, due to which the body's defense is formed. When infected with a real, active polio virus, they are activated, so that the disease does not develop or passes in a mild form, without causing paresis and paralysis.
Inactivated vaccine
A little earlier, in 1950, J. Solk had proposed an inactivated vaccine containing a dead virus. It is injected and released in the form of disposable syringes, the contents of which are one vaccine against polio. The vaccine schedule usually recommends using an inactivated vaccine for vaccination. IPV is administered intramuscularly in the thigh or shoulder. In the case of its use is not required to refrain from food and drink.
Numerous studies have confirmed that both vaccines can develop an effective and lasting immunity to a disease such as polio. The vaccination schedule allows the use of a particular vaccine depending on the individual characteristics of the child. The decision about this is usually made by the pediatrician, after conducting an examination and collecting a detailed history. Only after a child or adult has been thoroughly examined, is he allowed to vaccinate with a disease such as polio (vaccination).
Vaccination schedule
The vaccination calendar, which is the main document regulating the timing of immunization of the population in our country, prescribes vaccination against poliomyelitis in several stages. Moreover, in the first of them (vaccination) an inactivated vaccine is used, and in the subsequent ones (revaccination) - live. Such a scheme is considered optimal for obtaining stable immunity to the disease.
The first polio vaccine (a vaccination schedule will help young parents to navigate) is given by IPV at the age of 3 months. The next vaccination is also carried out IPV at 4.5 months, the third (OPV) - at 6 months. Then revaccination is carried out, which also occurs in three stages:
18 months (OPV);
20 months (OPV);
14 years old (OPV).
There are also immunization schemes that use only inactivated drugs. In this case, the vaccination passes:
3 months;
4.5 months;
6 months.
The following is a polio vaccine, the revaccination schedule of which includes the following dates:
As you can see, when using IPV, the schedule is somewhat reduced. Such schemes are used by many countries, it is not prohibited in Russia.
It should be noted that if, for some reason, the vaccination schedule is shifted, then you should not refuse subsequent vaccinations. 45 days, which are laid as the interval between the procedures, are the minimum period, and if you increase it, then nothing bad will happen. The formation of immunity during this time does not stop, and you do not have to start immunization again. That is, if any stage of vaccination was missed, then for a disease such as polio, the vaccination schedule will simply continue according to the scheme, and you will not have to start immunization again. In addition, it should be noted that OPV and IPV are interchangeable.
In addition to planned activities for children, adult immunization is also being carried out in Russia. This happens if a person travels to an area where there is a high incidence of this infection, or as a preventive measure in case of an outbreak.
Vaccine response
Although modern vaccines are generally well tolerated, an individual body reaction may follow in response to the vaccine. As a rule, it appears more strongly on OPV. This can be expressed in a rise in temperature to 37.0-37.5 Β° in the second week after vaccination. There may also be slight diarrhea within two days. Despite the fact that such a reaction is quite rare, it is normal and does not require special treatment. As a rule, all these disorders go away on their own.
With the introduction of IPV, there may be a slight swelling at the injection site, a slight rise in body temperature, impaired appetite, and anxiety are also possible.
Complications
The only serious complication of this vaccine is the vaccine-associated paralytic polio - VAPP. Fortunately, it is extremely rare. As a rule, it occurs after the first use of OPV (less often - during the second vaccination) and proceeds with all the signs of true poliomyelitis (paresis, paralysis, muscle atrophy). The risk of VAPP is high in children with low immunity, malformations, suffering from HIV or AIDS, if OPV is used for vaccination. To avoid complications, only IPV is used for this population for immunization.
Please note - an unvaccinated person (regardless of age), suffering from a decrease in immunity (HIV, AIDS) or taking drugs that suppress it, may become infected with VAPP from a child vaccinated with OPV, since within two months after vaccination it releases the virus into the environment.
Contraindications
The schedule of vaccinations against polio for children identifies the following contraindications for immunization:
acute diseases or exacerbations of chronic pathologies - vaccination is postponed for up to 4 weeks after recovery, in case of mild ARVI, vaccination can be carried out after normalization of temperature;
severe allergic reaction to vaccine components;
immunodeficiency, malignant tumors, immunosuppressive conditions;
neurological disorders that occurred during previous vaccinations.