What You Do Not Know About a Child's Immune System and Its Disorders


31. 08. 2023

Small children are especially vulnerable to various illnesses throughout the autumn and winter months. Parents sometimes feel that as soon as their child recovers from an illness, another one follows. So it continues with a runny nose until spring … Parents then often ask pediatricians whether something like that is “normal”, i.e. that their child is “almost constantly ill”. What is and isn’t considered normal and when to pay increased attention is all described in our article below.

A little bit of theory to begin

Generally speaking, the term “immune disorder” concerns the aspects of our immune system which protect us from foreign substances when they enter our body so as to prevent disease. However, the immune system is exceptionally complex. On one hand, it involves the body’s reaction to the penetration of our body by microorganisms (microbes, bacteria etc.). On the hand stands the opposite to immunity, i.e. allergies, where an organism reacts to antigens out of proportion and in an escalated manner. These often include triggers which would generally not be harmful to us (dust, pollen and more). The other extreme is autoimmunity, a state where we react to antigens of our own body as if they were foreign substances altogether.  

With very young children, the type od birth can affect their immunity

With adults, the immune system is fully developed. However, with children, it begins developing only after birth. Newborns can therefore be compared to blank sheet of paper where the first lines of text are being written at birth itself – i.e. exposure to antigens when passing through the birth canal and being subjected to them directly. 

In the first months of the child’s life, the baby is still protected by antibodies introduced to its blood supply from the mother. However, those gradually disappear and the child begins forming its own antibodies against individual antigens after being subjected to them. “This is why it is very important that the birth be carried out naturally, where the baby’s sterile digestive tract becomes colonized by the mother’s physiological flora when travelling through the birth canal. This is not the case for babies that are born through a Caesarean section. Birth through a c-section is a growing trend whereby we have many more children born through c-sections than spontaneously. This is then connected to the fact that colonization of their digestive tract is not entirely physiological. In addition, unless the child is breastfed, the structure of the flora is different to those children that were born naturally” explains pediatrician MUDr. Petr Žáček.

Children born through c-sections and not breastfed have a different bacterial flora in the digestive tract compared to what should actually be a bifidogenic one. They can therefore be disadvantaged with regards to the further development of the immune system, especially when it concerns allergies. This “deficit” occurs because their digestive tract experiences a delay in the colonization by lactobacilli which should already be there under normal conditions. Their so-called bifidogenic flora is often somewhat different to that of other children. “Children born through c-sections experience increased likelihoods of sensitization to inhalable antigens and asthma than those children born via the vagina. The risks are further strengthened in cases where parents suffer from allergies” adds MUDr. Žáček.

Increased exposure to illnesses is often necessary during the nursery period

Attending a nursery represents a major milestone for a child for various different reasons. This is also important from the viewpoint of immune system development. The transition from a relatively sealed-off environment of the family to being subjected to a collective of people means that the child is suddenly surrounded by many new sources of infectious diseases that the child has not yet been subjected to. It is therefore often a period of time when the child may be sick more often. This however also depends on how well developed the child’s immune system is. If it is already well-developed, the likelihood of infection is much lower. When the immune system is weakened, the child is more prone to infection and becoming ill more often.

The positive news about all this is that thanks to the various illnesses, the immune system of the child develops better. “The immune system is naturally strong enough to ensure that when we come in contact with viral, bacterial or any other infection, we are able to react to it, undergo the illness but not succumb to it. As a result we will be immune to it. Repeat exposure to the same antigenic structure (for example chickenpox) will result in the illness not developing. Of course, the situation changes when subjected to a disease with somewhat altered antigenic structure – for example with influenza where the antigen component is different each year and the antigen of the influenza virus is slightly different. The disease will then occur again. This also occurs and not only during childhood with common bacteria such as streptococci causing frequent illnesses” explains MUDr. Petr Žáček, pediatrician at Canadian Medical.

When should parents pay increased attention?

Generally speaking, it can be said that immune disorders result in the increased susceptibility to infections which tend to repeat themselves. These tend to last for a long time and the treated individuals respond poorly to treatment, often resulting in other complications. A child with enlarged adenoids can be considered to represent a typical example associated with immune disorders. However, “increased adenoids are not an immune disorder. The primary cause is not a weakened immune system but rather a mechanical obstruction in the nasopharynx. This situation represents a breeding ground for bacteria carrying with it the various consequences” further explains pediatrician Petr Žáček.

A chronic, untreated and mismanaged infection weakens the immune system, resulting in the overall weakening of the whole body. “I would certainly be concerned when the child would experience more than six acute infections within 6 months, i.e. being ill once a month for a period between a week or ten days. In such a case, I would consider carrying out immunological tests. It would be good to visit a pediatrician who would have enough time to devote to the child and parents, understand the child’s medical history and how the disease developed. Also the doctor should determine whether the child regularly goes for preventive checks and in case of being ill to the doctor” explains MUDr. Žáček. With the help of specialized examinations, it is possible to determine the causes of being ill frequently and to administer the appropriate treatment.

How can we boost the child´s immune system?

“The level of immunity of the body is related to how well-nourished and hardened the child is as well as the environment that he/she is subjected to – whether the environment is not polluted or the family smokes etc. This all affects non-specific immunity. When anyone lives in a highly-polluted environment, the primary defenses are damaged and this further makes it easier for bacteria and viruses to enter the organism. Overall weakening when the body is subjected to cold and not hardy enough will allow the body to be infected easier. We then try to discover whether the body also has a weakened specific immunity, be it antiviral or antibody related. The solution rests in follow-up support and administering the appropriate medication” states pediatrician Petr Žáček.

Especially during the winter months, it is possible to strengthen the immune system of children by using herbal medicine. These can be various extracts derived from mushrooms, plants or yeasts based on specific recommendations from experienced pediatricians. Appropriate and sufficient nutrition along with an intake of vitamin D plays an indispensable role. Vitamin D affects not only the child’s growth, but also the immune system during periods when there is very little sunlight. This applies to both adults and children alike.


MUDr. Petr Žáček, pediatrician at Canadian Medical

Articles and news


The Sweetest Life (but without the diabetes)


Unhealthy lifestyle: a road to disease


Flu vaccination? We recommend it to everyone


Obesity is becoming increasingly prevalent among younger individuals


Canadian Medical is an accredited and certified workplace


New doctors to our Canadian Medical clinic teams


Vasectomy. Questions and answers


The future of health is in digitization


Flu vaccination begins

Sign up for our newsletter