Children's immunity: features of formation, signs and causes of weakened work

Why does a child have a weak immune system? To understand this issue, we have collected information that explains the principle of work, the features of the formation of immunity in children and the reasons for its decline in babies under one year old and older children. Even from the article, parents will learn by what signs it is possible to determine that the child has weak immunity.

What is immunity and how does it work?

When various viral or bacterial infections make their way into the human body, it begins to actively fight them. The ability of the immune system to fight various types of infections that enter the body is called immunity.

Immunity - a set of physiological processes and mechanisms aimed at maintaining the antigenic homeostasis of the body from biologically active substances and creatures that carry genetically alien antigenic information or from genetically alien protein agents.

Classification of immunity

Distinguish congenital ( species) and acquired immunity . Species (congenital, hereditary) immunity goes to the baby by inheritance. Acquired immunity accumulates throughout a person's life and is divided into natural and artificial.

Natural (acquired) immunity divided into active and passive. Active natural immunity accumulates gradually after successful fight against this or that infection. Not all past diseases contribute to the formation of lifelong immunity. A child can carry some diseases several times after the next contact with the microbe. If a child has been ill with rubella or, then in almost all cases he will acquire stable lifelong immunity against these diseases. The duration of immunity depends on the ability of the microbe to elicit an immune response. Passive natural immunity It is formed by antibodies that are passed from mother to child through the placenta during pregnancy and through milk during breastfeeding.

artificial acquired immunity divided into passive and active. active immunity formed after the . Passive Immunity appears after special serums with antibodies are injected into the human body. The duration of such immunity is measured in several weeks, and after the end of this period it disappears.

The concept of the immune response and its types

immune response- this is the reaction of the body to the ingress of any alien microbes or their poisons into it.

Types of immune response:

• Nonspecific immune response activated almost instantly, as soon as the microbe enters the body of the child. Its goal is to destroy the microbe by forming a focus of inflammation. The inflammatory reaction is a universal protective process aimed at preventing an increase in the field of activity of the microbe. The general resistance of the body directly depends on nonspecific immunity. Children with weakened nonspecific immunity are most susceptible to various diseases.
• specific immune response T - the second stage of the occurrence of protective reactions of the body. At this stage, the body tries to recognize the microbe and develop protective factors that will be aimed at eliminating a certain type of microbe. Specific and non-specific immune responses invariably intersect and complement each other.

The specific immune response is divided into cellular and humoral:

• When it works cellular specific immune response , clones of lymphocytes are formed, seeking to destroy targets, the membranes of which contain foreign materials, such as cellular proteins. Cellular immunity helps eliminate viral infections, as well as some types of bacterial infections (such as tuberculosis). In addition, activated lymphocytes are an active weapon in the fight against cancer cells.
• Specific humoral immune response acts through B-lymphocytes. After the microbe is recognized, they actively synthesize antibodies according to the principle of one type of antigen - one type of antibody. During all infectious diseases, antibodies always begin to be produced. The humoral immune response develops within a few weeks, it is during this time that the necessary amount of immunoglobulins is formed in the body in order to completely neutralize the source of infection. Clones of lymphocytes are able to remain in the body for quite a long time, therefore, upon repeated contact with microorganisms, they give a powerful immune response.

There are several types of antibodies (immunoglobulins):

• Type A antibodies (IgA) needed to provide local immunity. They try to prevent the penetration of microbes through the skin or mucous membranes.
• Type M antibodies (IgM) activated immediately after the child had contact with the infection. They are able to bind several microbes at the same time. If type M antibodies (IgM) were detected during a blood test, then they are evidence of the emergence and growth of an acute infectious process in the body.
• Immunoglobulins type G (IgG) able to protect the body from the penetration of various microorganisms for a long time.
• Type E antibodies (IgE) - protection of the body from the ingress of microbes and their poisons through the skin.

How immunity is formed in children: five critical periods in the life of children

The immune system of the crumbs begins to form even during fetal development, when strong ties are established between the body of the mother and the child. The baby's own M antibodies begin to be produced in small quantities in the baby around the twelfth week of pregnancy, and their number increases immediately before childbirth.

In addition, T-leukocytes appear in the body of the crumbs by the 12th week of pregnancy, the number of which increases on the fifth day of the baby's life. In the first months of a child's life, maternal antibodies protect, since the baby's body is practically unable to synthesize its own immunoglobulins. The required amount of type M antibodies approaches adult levels only by 3-5 years of a child's life.

There are five critical periods in the life of children that affect the formation of the immune system:

1. Neonatal period (up to 28 days of a child's life). The baby is under the protection of maternal immunity, while his own immune system is just beginning to form. The child's body is susceptible to the effects of various kinds of viral infections, especially those from which the mother did not pass on her antibodies to the baby. At this time, it is extremely important to establish and maintain breastfeeding, as breast milk is the best protection for the baby.
2. The period from 3 to 6 months of a child's life. At this time, maternal antibodies are destroyed in the baby's body, active immunity is formed. During this period, SARS viruses begin to act especially actively. In addition, babies can easily catch an intestinal infection and suffer inflammatory diseases of the respiratory system. The baby may not acquire antibodies from the mother to diseases such as whooping cough, rubella, chickenpox if she does not have vaccinations or she did not have them in childhood. Then there is a high risk that these diseases can occur in the baby in a rather severe form. The likelihood of a recurrence of the disease is high, because the infant's immunological memory has not yet taken shape. There is also a high risk of allergies in a child, primarily to food.
3. The period from 2 to 3 years of a baby's life. The child actively learns about the world around him, but the primary immune response still dominates in the work of his immunity, and the local immunity system and the production of type A antibodies remain rather immature. Children during this period are most susceptible to bacterial rather than viral infections, which can be repeated repeatedly.
4. Age 6-7 years. During this period, the child already has baggage with accumulated active immunity. However, parents should be concerned that the disease may become chronic. In addition, there is a high risk of allergic reactions.
5. Adolescence. In girls, it begins at 12-13 years old, in boys a little later - at 14-15 years old. At this time, there is a rapid growth and hormonal changes in the body, which are combined with a decrease in lymphoid organs. Chronic diseases are making themselves felt with renewed vigor. In addition, the child's immune system is tested if the teenager is faced with bad habits.

Weak immunity: the main signs

Signs of reduced immunity in children of different ages:

• in young years.
• A child often has prolonged acute otitis media, and a runny nose will certainly turn into sinusitis or sinusitis. There are problems with adenoids, as well as palatine tonsils.
• Constant tearfulness and irritability, poor short-term sleep.
• Bad appetite.
• Pale skin.
• Poor bowel function. The stool is irregular or too frequent, or loose, or the baby has difficulty emptying the bowels.
• The child recovers for a very long time after being ill.
• Frequent occurrence of fungal infections.

Factors that reduce children's immunity

Causes of reduced immunity in infants:

1. Trauma during passage through the birth canal.
2. Severe pregnancy.
3. Poor heredity and predisposition to infectious diseases.
4. The baby refused breast milk before reaching the age of six months.
5. Improper complementary foods with an excess or lack of essential nutrients.
6. Malfunction of the digestive tract.
7. Drug overdose.
8. Severe psychological trauma.
9. Poor ecology, especially in areas with high radiation.

Causes of reduced immunity in school-age children:

1. Recurrent diseases of the ear, throat, nose.
2. Improper diet, including eating foods that are high in nitrates or pesticides.
3. Stress and constant nervous tension.
4. The emergence of conflicts leading to misunderstanding and rejection in the team.
5. Abuse of TV, computer, other modern gadgets.
6. The minimum amount of time the child spends on the street, does not rest. Fatigue and unbearable workload: school plus a lot of additional circles and sections.
7. In spring and autumn, allergies are exacerbated every year.

If the immunity of the child is weak, then it is necessary to strengthen it. How to do this will tell the article "How to strengthen the immune system."