How Does A Child’s Immune System Develop?

Development of a child’s immune system begins in the womb. Here, although the organs and structures associated with the immune system are present, the activity of the immune system itself is low. In the womb, the mother transfers numerous antibodies to the foetus via the umbilical cord. These are trained to recognise organisms which the mother herself has been infected with during her lifetime, and so confer a level of protection to the infant once it is born.

Once a baby is born, it is suddenly exposed to a huge variety of antigens (molecules that the immune system can recognise) and foreign organisms. This is thought to be one reason why an infant’s immune system is suppressed during the first few months of life, as it could easily become overwhelmed and cause serious health issues. This also allows good bacteria transferred from the mother during birth to begin to colonise the baby’s intestines.

After birth, a child’s immune system begins to develop rapidly. This process is complex and not fully understood, with certain cells becoming active and transforming into new types of cells at specific stages.  During this stage, maternal antibodies are still active, protecting the baby while its immune system learns and develops. Breastfeeding also transfers protective antibodies to the infant, and can thus extend the protection offered by the mother. Maternal immunity generally does not last longer than about 6 months.

As the infant’s adaptive immune system becomes active, so does the extremely important and long process of training their immune system. From this point on, their body will be constantly learning to recognise what is dangerous, and how to defend against it. It is generally thought that a child’s immune system becomes mature at about 3 months. All this means, however, is that it is able to begin defending against and recognising invaders. It will still take a number of years before it is adequately able to recognise the numerous germs that can infect us.

How Can I Help Prevent My Child From Getting Sick?

Children will naturally get sick and it is impossible to completely protect them from invading organisms. It is possible, however, to prevent them from getting sick as often, and to speed up recovery. Most advice is centred upon encouraging a healthy lifestyle, ensuring the complex process that is the development and function of their immune system is optimal. The next best way to help prevent disease is to ensure your children are up to date with their vaccinations. To read more about vaccines, scroll to the bottom of this link.

Make sure that your children understand and practice good hygiene, regularly washing their hands, avoiding others who are sick, and being able to recognise something that potentially harbours infectious organisms. It is also good to teach them how to lower the risk of infecting others when they are sick, like by covering their mouths when they cough and washing their hands before touching anything that might be touched by others. Most common pathogens are either spread through the air or through touching infected surfaces.

Do I Need To Keep My Child Away From Germs Or Make Their Environment Sterile?

While maintaining hygiene is an important part of keeping healthy and avoiding infection, a developing immune system needs to learn to recognise what is dangerous and what is not, as well as develop immunity to as many organisms as possible. To keep your child safe, you should encourage regular hand washing, keep their environment clean and make sure they know what is safe to touch. To ensure their immune system develops properly and learns to control its response to every day challenges, however, it is necessary that they are exposed to environmental bacteria, viruses and allergens like pet fur. Children learn by holding, playing and chewing on new objects and things they find. Keeping them away from germs is therefore almost impossible. Instead of letting this stress you out, consider it a learning experience – not just for their minds, but for their immune systems too.

Most of the germs children come into contact with will stimulate the immune system and be removed and remembered for future. This prevents infection later in life, as well as allergic reactions to the environment once the immune system is fully developed. Allowing them to come into contact with low doses of viruses and bacteria can also help protect them at a later stage if they are infected by a larger dose of the same organism. Every day we inhale or ingest numerous harmful microorganisms, but because it is only one or a few the immune system can overcome them easily. When we ingest a large amount, like if eating infected food, the immune system struggles to dispose of all the pathogens before they establish an infection. For example, your child placing a small amount of E. coli present in the soil in their mouth is unlikely to cause disease, but does allow the immune system to learn to recognise it. Severe disease at a later stage if they ingest food or water contaminated with E. coli is therefore less likely.

How Can I Help Strengthen My Child’s Growing Immune System?

A child’s immune system is constantly changing and growing. In order to ensure that they have a strong and optimally functioning immune system, it is essential to ensure you do all you can to give it what it needs during this essential stage of development.

In order to strengthen your child’s immune system:

• Ensure they receive a diet high in plant-based sources of nutrition. This should contain good sources of magnesium, selenium, zinc, iron and the vitamins A, C, D and E. If you are worried that your children are not receiving enough of these from their diet, you can give them a supplement designed to enhance immune function. Contact the MNI dietician at dietician@mnilifestyle.co.za for healthy diet tips for you and your children.
• Avoid processed foods and sugar. These have been linked to many health problems, including reducing the effectivity of the immune system and promoting inflammation.
• Make sure they receive adequate amounts of good quality sleep. Sleep is important to a wide range of functions, and many developmental processes occur or are enhanced during sleep. This includes immune system development and function. Children should receive between 10 – 14 hours of sleep, depending on their age.
• Reduce stress. This not only includes helping them to deal with issues at school and extramural activities, but promoting a family routine through ensuring meals, playtime and bed time (amongst others) occur at set times each day. Routine can be one of the best ways to reduce stress.
• Ensure the environment is free from harmful substances. This is especially true for second hand smoke.
• Encourage them to exercise and go outside regularly. This will not only help strengthen their immune system but also has a wide range of other benefits, including helping them establish a lifelong fitness routine.
• Focus on healthy bacteria. The microbiome, or the normal suite of bacteria which live on and in us, serve many helpful roles in maintaining optimal health. Not only can they provide us with nutrients which may otherwise be inaccessible, but they also help prevent infection. Beneficial bacteria crowd out invaders and prevent their attachment, regulate our immune system and even produce their own antibiotics. The best way to help your children develop a healthy microbiome is to provide them with substances called pre and probiotics. Probiotics are small amounts of living healthy bacteria, and can be found in supplements and fermented foods such as certain types of yogurt. Prebiotics are the food which these bacteria eat, helping them to stay healthy and maintain adequate numbers to stave off potential infections. An important component of prebiotics is fibre, and while it can be supplemented, it is best sourced from unprocessed, plant-based food sources such as fruits and vegetables.

When Should I Take My Child To The Doctor (Colds & Flu)?

If you are in doubt at all about whether to visit the doctor, it is always best to take your child for a consultation or call your paediatrician to make sure. The younger your child, the more important this is.

Colds and flu will usually clear up on their own and generally require only over the counter treatment. In some cases, however, they can cause greater health issues, either by themselves, or because they can open the door to secondary, more dangerous infections. It is best to ensure you can recognise the signs that a cold or flu is developing into something more dangerous.

You should seek medical care or advice if your child is experiencing:

• Persistent low grade fever
• If the illness is getting worse, new symptoms develop, or the symptoms or illness are not getting better
• Pain that is not reduced by over the counter medicines
• Frequent vomiting or diarrhoea
• Your child is under the age of three months
• Refusal to eat or drink

You should seek immediate medical attention if your child is experiencing:

• Difficulty breathing
• A high and persistent fever
• Skin colour changes
• Dizziness, confusion or seizures
• Dehydration
• Severe rash

Fever

What Is A Fever And Is It Dangerous?

A fever is one of the many natural and normal responses of the body to infection. Most infectious organisms can only live, develop and reproduce efficiently at normal body temperature (37°C). When we become infected, the immune system signals to a structure at the centre of our brain, the hypothalamus, which is responsible for temperature regulation. It responds by increasing our body’s temperature, making it harder for the invading organism to spread and cause disease.

A fever is a body temperature over 38°C. It is very rare for an infection to cause a body temperature that is dangerously high, as the hypothalamus strictly regulates how high it should go. Most fevers don’t go past 40°C, and rarely past 41°C. Even though these fevers are high, they will generally still not cause harm. Dangerously high body temperatures are only really observed during hyperthermia, or when heat exposure, such as from being stuck in a locked car, makes it impossible for our body to adjust through normal mechanisms such as sweating.

It is important to note that depending on how you measure body temperature, normal temperature can be different. For example, a reading of 37.2°C and above using an armpit thermometer is considered a fever, while the threshold for an oral reading is 37.8°C. Be sure to check the threshold for fever according to the specific thermometer type you are using.

While a fever is often thought of as dangerous, it is therefore actually a very normal response to infection, and in most cases is beneficial.

When Should I Be Worried About A Fever?

Fevers may be seen as problematic in the following cases:

• It lasts longer than 3 days: this is a sign that the infection is not clearing.
• It is accompanied by worrying behavioural changes that would be considered more severe than what is observed normally during a cold or flu, such as refusal to eat and drink, lethargy or if your child appears seriously sick.
• Temperature above 39°C.
• Your child is younger than 3 months.
• You are pregnant.
• Your or your child is immunocompromised.
• Your child’s fever does not respond to over the counter medication.
• Any of the following symptoms are experienced:
  • Seizure
  • Loss of consciousness or confusion
  • Stiff neck
  • Trouble breathing
  • Severe pain or swelling at any part of the body
• You are worried. It is always better to be safe than sorry. Rather call your doctor or pay them a visit if you are unsure.

How Should I Treat A Fever?

It is not usually necessary to treat low grade fevers (below 38.9°C) unless a doctor recommends it, and doing so may prolong the infection as lowering body temperature would allow the infection to spread. Treatment is usually symptomatic, and is recommended to make your child more comfortable.

Treatment of fevers can be achieved through using over the counter medicines such as paracetamol. Ask your pharmacist for a recommendation. Keep in mind that most of the normal symptoms of infection are actually your body’s defence against illness and so treating them can reduce the efficacy of your body’s response. Treatment should only take place when your child is feeling uncomfortable. It is important to note that once the medicine wears off the fever will return. This should not be any cause for concern. Once the body has control of the infection, usually after two or three days, the fever will subside.

Furthermore, ensure that your child is receiving enough liquid to prevent dehydration. For higher temperatures, placing the child in a lukewarm bath or a damp cloth on their forehead can provide some relief. Do not place them in cold water as this can cause more discomfort. Wrapping your child in blanket or clothes can also be problematic. Even though they may feel cold and be shivering, remember that their body temperature is actually above average. Doing this can therefore cause further body temperature rise or issues with temperature regulation.

What Are Febrile Seizures?

Febrile seizures are a relatively rare side effect of fever, occurring in only 2-4% of children under the age of 5. Of children who have febrile seizures, 40% will have another one in future, and children who are related to them are more likely to have one. While they may be unnerving and cause you to worry, they are not usually dangerous. Febrile seizures of normal duration, and even those that last over 15 minutes, do not appear to have significant negative effects, and are not linked to epilepsy.

Febrile seizures usually only last a few minutes. The signs that your child is experiencing a febrile seizure include:

• Passing out
• Jerking movements
• Eye rolling
• Rigid/stiff limbs

If your child experiences a febrile seizure, lower them onto a protected surface such as the floor and place them on their side. Do not place anything in their mouth or try to subdue/hold them down. Following a seizure, immediately contact your doctor. If the seizure lasts longer than 5 minutes, multiple seizures occur, your child exhibits problems breathing, their skin colour changes or your child does not recover quickly following a seizure, seek immediate medical attention.