Polio 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 vaccinations against polio helped to do this. The schedule in Russia provides for their implementation in the first months of a child's life.
Polio
Polio is an acute infection caused by a virus that has three serotypes. The source of infection are sick people and virus carriers. The disease is transmitted by the fecal-oral and droplet route. That is, you can get infected through contact, through water, dishes, products that have got the virus. In the external environment, it is sufficiently stable that it can provoke epidemics. Children from 3 months to 5 years are most susceptible to its action. In typical forms of polio, the virus infects the motor nuclei of the brainstem and spinal cord. Clinically, this is expressed either by meningitis, or by the development of paralysis, paresis, and muscle atrophy. The disease may also be asymptomatic orerased form. Lifelong immunity is maintained by a person who has had polio. 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 had polio, a person can become infected with it again, but a different type of virus will act as the causative agent.
Types of vaccines
To date, two types of vaccines have been developed. A distinction is made 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 among the population, and to create immunity to such pathologies as poliomyelitis. Vaccination (the schedule of vaccinations will be presented below) can be done with both OPV and IPV. Both versions of the vaccine contain all three types of the 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 preparation "Tetrakok", which is used with simultaneous vaccination against diseases such as diphtheria, tetanus, whooping cough, poliomyelitis. The vaccination schedule from the latter allows two schemes. One of them uses IPV for vaccination, and OPV for revaccination, while the other involves the introduction of only IPV.
Oral vaccine
OPV was developed in 1955 by the American virologist A. Sabin. It contains a live but weakened virus. ExternallyThe vaccine is a red liquid with a bitter taste. The vaccine is administered through the mouth, by instillation, depending on its concentration, from 2 to 4 drops. The polio vaccination schedule for children under one year of age recommends instilling the vaccine on the root of the tongue to prevent spitting up. In older people, it is instilled into the palatine tonsil. After the procedure, food and drink should be excluded for an hour. If the baby does burp, the same dose is given again.
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, thanks 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. Salk proposed an inactivated vaccine containing a killed virus. It is administered by injection and is available in the form of disposable syringes, the contents of which are one vaccination against polio. The vaccination schedule generally recommends the use of an inactivated vaccine for vaccination. IPV is administered intramuscularly in the thigh or shoulder area. It is not required to refrain from eating and drinking when using it.
Multiple studies have confirmed that both vaccines provide effective and durable immunity to a disease such as polio. The vaccination schedule allows the use of one or anothervaccine, depending on the individual characteristics of the child. The decision on this is usually made by the pediatrician, having previously conducted an examination and collected a detailed history. Only after a child or adult has been thoroughly examined is he allowed to be vaccinated for 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 polio in several stages. At the same time, in the first of them (vaccination), an inactivated vaccine is used, and in the subsequent ones (revaccination), a live one is used. Such a scheme is considered optimal for obtaining sustainable immunity to the disease.
The first polio shot (the vaccination schedule will help new parents navigate) is given by IPV at 3 months of age. The next vaccination is also carried out with 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 regimens that use only inactivated drugs. In this case, vaccination passes:
- 3 months;
- 4, 5 months;
- 6 months.
Followed by the polio vaccine, the booster schedule of which includes the following dates:
- 18 months;
- 6 years.
As you can see, when using IPV, the schedule is somewhat reduced. Such schemes are used by many countries, and it is not prohibited in Russia either.
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 down as an interval between procedures, are the minimum period, and if it is increased, then nothing terrible will happen. Immunity formation will not stop during this time, and you will not have to start immunization again. That is, if any stage of vaccination was missed, then from a disease such as polio, the vaccination schedule will simply continue according to the scheme, and you will not have to start immunization all over again. In addition, it should be noted that OPV and IPV are interchangeable drugs.
In addition to planned activities for children, immunization of the adult population is also carried out in Russia. This happens when a person travels to an area where there is a high incidence of this infection, or as a preventive measure in the event of an outbreak.
Vaccination reaction
Despite the fact that modern vaccines are usually well tolerated, in response to a vaccination, an individual reaction of the body may follow. As a rule, it manifests itself more strongly in OPV. This can be expressed in an increase in temperature up to 37, 0-37, 5 ° in the second week after vaccination. There may also be mild diarrhea for two days. Even though this reactionis quite rare, it is normal and does not require special treatment. As a rule, all these disorders go away on their own.
When IPV is injected, there may be slight swelling at the injection site, a slight rise in body temperature, loss of appetite, anxiety.
Complications
The only serious complication of this vaccine is vaccine-associated paralytic poliomyelitis - VAPP. Fortunately, it is extremely rare. As a rule, it occurs after the first use of OPV (less often - with the second vaccination) and proceeds with all the signs of real poliomyelitis (paresis, paralysis, muscle atrophy). The risk of VAPP is high in immunocompromised children with HIV or AIDS who are vaccinated with OPV. In order to avoid complications for this contingent, only IPV is used for immunization.
Please note - an unvaccinated person (regardless of age), suffering from reduced immunity (HIV, AIDS) or taking drugs that suppress it, can become infected with VAPP from a child vaccinated with OPV, as he secretes virus into the environment.
Contraindications
The Polio Immunization Schedule for Children highlights the following contraindications for immunization:
- acute diseases or exacerbations of chronic pathologies - vaccinationdelayed for up to 4 weeks after recovery, in case of a mild SARS, vaccination can be carried out after the temperature returns to normal;
- severe allergic reaction to vaccine components;
- immunodeficiency, malignancy, immunosuppressive conditions;
- neurological disorders from previous vaccinations.
