Understanding children’s immunity
The body is uniquely able to protect and heal itself from injury and disease, and to maintain a state of internal harmony, due to a series of intricate mechanisms that make up the immune system. The immune system is a kind of surveillance system which checks for ‘foreign entities’ entering the body or if they are out of place in the body, and then activates processes to remove them.
Often signs and symptoms of illness are actually evidence of the body carrying out its self-cleansing process to clear whatever pathogens have caused an imbalance in homeostasis (1). The role of medicine is really to assist the efforts of the body to heal itself, rather than to suppress the symptoms of clearing mechanisms.
Children and babies are prone to experience frequent colds, coughs, catarrh, and ear infections. The mucous produced in such cases is doing its job to protect, eliminate, and clear pathogens or irritants that have triggered the immune response. Giving medicines to control symptoms at the first sign of a sniffle or sickness in a child, such as mucous, fever, diarrhoea, or vomiting, can often be more damaging then helpful because it will suppress the body’s natural defences, and potentially send the illness further into the body stimulating a more chronic state. These symptoms are the body’s immune system working to eliminate infections, and so if the body’s defences are working well, it is usually helpful to allow them to do their job without supressing them. Of course, in some cases, for example if symptoms persist or a fever rises suddenly then medications can be helpful.
Herbs generally work to support the body’s natural defences, rather than to supress symptoms, and to allow the system to work smoothly so that it returns to a state of health and vitality, functioning as it is designed to. This can be a wonderful source of support to the developing immunity of children, acting to support, nourish and balance the system so that it can function at its best, unaided.
How does children’s immunity work?
The immune system is a complex network consisting of organs, tissues, and cells within the body which in very simple terms will initiate production of necessary immune cells to destroy and eliminate pathogens in order to keep the body healthy. This includes ‘foreign entities’ entering the body from the external environment, and cell debris within the body from dead cells (which are being replaced all the time) that need clearing up.
The main focus of the immune system is on antigens, these are protein-based substances which cause the immune system to produce antibodies against them. A full overview of the immune system and cells involved can be seen in our Immunity article.
Here we will look specifically at children’s immunity: the important thing to understand about this is that children’s immunity is still developing, leaving them more prone than adults to most microbial infections, and as babies and young infants particularly prone to experiencing more severe symptoms (2).
The innate immune system is the first line of defence, which deals with parasites, allergic reactions, bacteria, and recycling dead cells. Cells of the innate immune system already present in new-born babies include monocytes, macrophages, dendritic cells, and neutrophils, but monocytes and macrophages at this stage are immature, and have a lower cytokine response than in adults (cytokines are proteins responsible for control and growth of other immune cells). After birth, the number of neutrophils stabilizes but they have only weak activity towards bacteria. Due to the somewhat muted innate immune system in new-borns, this results higher than in the adults, susceptibility to bacterial and viral infection. The innate immune system is also responsible for activating adaptive immune responses.
Adaptive (or specific) immunity involves immune cells called lymphocytes, made up of B cells and T cells which are responsible for the majority of antibody formation, and Natural Killer (NK) cells which kill damaged or infected cells and call in other helper cells to clear up and prevent infection. B cells and T cells are present in babies and developing children but are different to those in the mature immune system. The thymus gland is involved in the production and storage of T cells, to assist cells infected by bacteria, fungi, and viruses and those involved in adaptive immunity which is developing in children. Therefore the thymus gland is particularly important in the establishment of children’s immunity (1).
The spleen, liver, tonsils, adenoids, and intestinal wall contain lymphoid tissue, which is involved in the production of lymphocytes. In fact, the gut wall contains around 70% of the lymph cells found in the body and are responsible for the important job of responding to all antigens that enter the body through food entering the digestive tract (1).
So, we can see that the immune system itself is complex, and childhood is an important time as the immune system develops, placing emphasis on ensuring that children receive the best foundation for the immune system to develop in a healthy way. This can actually include exposure to a variety of bacteria’s and viruses during childhood through contact with other people and the surrounding environment, so that the body can develop a natural immunity against them should they be encountered again. This is alongside providing a sufficient nutrition through a balanced diet. By the age of 7 -8 years the immune system tends to mature.
Understanding the root of children’s immunity
Children’s immunity is constantly encountering new pathogens and learning how to process or deal with them, leaving children prone to experiencing frequent colds, stomach upsets, or other mild acute (short-term) illnesses which are easily passed around with close contact between children in nurseries and school environments. An undeveloped immune system leaves children more prone to infections than adults and up to 30% of viral respiratory infections in children develop into bacterial complications, which can call for antibiotic treatment (3). Many bacterial infections are becoming resistant to antibiotics, and antibiotics have their own impact on the immune system disrupting the natural microbiota which is important for healthy immunity. Due to antibiotic resistance, there have been campaigns over recent years for doctors to reduce the use of antibiotics, especially in children, but despite these efforts in the UK they are still being prescribed in a high number of cases (67 – 90%) for common childhood ailments of respiratory tract infections (3).
If acute illnesses in children frequently leads to infections or become long-lasting, requiring antibiotic treatment, this is an opportunity to explore what is behind this susceptibility to ill-health, and why the immune system is struggling to maintain a healthy state of balance, and ‘bounce back’ as it is naturally designed to. For this we can look at other factors which can be altered to better support immune health, and herbs are one part of this which can provide much needed support in this new area of antibiotic resistance, where prevention of infection through deeper immune system support can play a huge role.
There are many factors which can influence immune health in children, such as genetic predisposition, environment and lifestyle which includes emotional stress, diet, exercise, quality of sleep and time spent in nature. All of these will contribute to how well a child’s immune system is able to sustain everyday encounters with pathogens and keep the body healthy. This also means that if a child is experiencing frequent bouts of ill-health, in many cases there are many simple changes that can be made which will help support them in experiencing better health.
There has been a rise in issues with children’s immunity in the last few decades, with atopic conditions (allergies) such as allergic rhinitis, asthma, and atopic dermatitis (eczema) becoming common. There is increasing evidence indicating potential links between the gut microbiome and the development of allergies. It is no surprise then that many environmental factors which are linked with the development of allergies, such as antibiotic use, caesarean delivery, and dietary habits also largely effect the gut microbiome (4).
The microflora in early life is highly unstable and undergoes dynamic changes during the first few years, converging towards a more stabilized adult microbiota by co-evolving with the host by the age of 3–4 years. Microbiota studies have underlined the role of dysbiosis (imbalances in the gut microflora) in developing several metabolic disorders like obesity, diabetes and immune-related disorders like asthma, to name a few (5). This shows the important role the gut microbiome plays in the root of immune health in children, and also for their future health.
Alongside this, other factors which affect immunity are diet (in terms of nutrients and variety of whole foods), ability to absorb nutrients (again coming back to gut health), and stress, which can impact on immune function. All of these can be explored when considering the root of how well children’s immunity is functioning.
Signs and symptoms
These are some common health conditions in children which affect their immunity:
- Coughs and colds
- Ear infections (otitis media)
- Sinusitis
- Allergies (rhinitis, asthma, eczema)
- Conjunctivitis
- Gastrointestinal upsets (vomiting / diarrhoea)
Herbal solutions
The aim with herbal support of children’s immunity is very much about regulating and restoring healthy, balanced immune function, so that children are strong and resilient long term. There are many herbs which can provide various types of support to children’s immunity, some of which will be helpful to have in the cupboard for acute infections such as coughs and colds. However, if you are looking at more complex or ongoing immune issues in children such as recurrent infections or allergies, seeking the help of a herbalist is advisable. You can find herbalists on our Resources page.
This provides an outline of which herbs help to support different aspects of immune function in children:
- Herbs which help to enhance the body’s antibody response to antigens include: echinacea*, golden seal, ginseng.
- Herbs which increase natural killer (NK) cells: liquorice, garlic, ginseng, mistletoe, Ganoderma (reishi), shitake.
- Herbs which regulate T cell response (which can stop infections and inflammation from persisting): garlic, ginseng, astragalus, liquorice.
- Herbs which help boost specific B cell derived antibodies:
- Liquorice and schizandra increase supply of antibody IgA which is found in respiratory and upper digestive tract.
- Echincaea* and golden seal increase IgG which can speed up resolution of infections in early stages.
- Herbs help with B cells involved in tackling recurrent infections: liquorice, ginseng, ashwagandha, astragalus.
- Herbs that can help to modulate IgE-mediated allergic reactions: echinacea, garlic, golden seal, feverfew, turmeric, chamomile.
*Echinacea is in the Asteracea plant family, and occasionally people exhibit allergic reactions to plants in this family (including daisies and chamomile). If a child has a known allergy to these plant then it is best to avoid giving them echinacea.
Specific herbs particularly helpful for children’s ailments and how they are help in supporting children’s immunity:
Liquorice is an excellent herb for children because as well as all the benefits for immunity its sweet taste increases the likelihood of compliance in taking it. It works on regulating immune responses so will help to restore healthy immune function and has antiviral properties. It is also helpful for reducing inflammation partly because of its restorative effects on immune function, but also because of its demulcent properties. This makes it soothing and healing for mucous membranes which can help in the digestive tract improving overall gut health, and also in the respiratory system with coughs. Liquorice is excellent in the case of allergies and topically for symptomatic relief of atopic dermatitis.
Because it is beneficial for so many aspects of immunity, Liquorice can be added to most herbal formulations for children to add a sweet taste and increase the likelihood of children taking them.
Liquorice is best avoided in cases of severe diarrhoea because it can have a slightly laxative effect.
Echinacea helps to modulate the immune system (it boosts it when low, and reduces it when overactive). It can enhance immune function, works on lymph tissue throughout the body, and works to limit acute and chronic infections furthermore preventing their onset (6). It is indicated in respiratory tract infections, skins conditions, and gastrointestinal conditions, all of which are common ailments in children.
A recent study of over 150 healthy children between 4 – 12 years old were allocated to a study and control group over a 4 months period given given tablets delivering 400 mg of Echinacea purpurea extract 3 times daily, at a preventative daily dose of 1200mg (50% of an adult preventative dose). A control group were given tablets containing 50mg of vitamin C, three times daily a daily dose of 150mg. The results of the study reported that use of Echinacea, compared to the control of vitamin C resulted in significant prevention of cold days and respiratory tract infections by up to 32.5%. This includes specific prevention of enveloped virus infections, including respiratory syncytial virus and in particular a marked reduction of influenza virus infections. There was a reduction in respiratory tract infection complications by 65% and lastly, antibiotic prescriptions were reduced by up to 76.3% for 103 children taking Echinacea for 4 months (3).
The safety of Echinacea was very good with very low numbers of adverse events thought possibly related to study medication. This study demonstrates how beneficial herbs such as echinacea (based on the specific formulation provided in the study) can be in supporting the immunity of children and preventing common complications which often lead to antibiotic use.
In 2012 a warning was issued by the MHRA that as a precautionary measure the remedy echinacea should not be given to children under 12 years old, due to a small risk of a severe allergic reaction which outweighed any benefits (7). However, since this time there has been research demonstrating the significant benefits of echinacea for children in reducing RTI’s and subsequent antibiotic use with minimal allergic reactions within the study group (3). This was based on a specific extract of echinacea, but suggests that unless there is a specific known allergy to this plant family then echinacea can have many benefits to children’s immunity.
Elderberries are immune enhancing andincrease antibody response to infection. Traditionally elderberry has been used as a flu remedy for centuries and is also high in vitamin c (1). Elderberry syrup is often a popular option for children because it is palatable and provides many benefits for immune support. Elderberries must be prepared properly as when eaten raw they can cause nausea and diarrhea.
Holistic solutions
The best approach for supporting immunity in children is a combination of lifestyle, stress-management, exercise, diet, and the use of plant-based medicines (8).
Diet
Ensuring that children eat a balanced diet can have a big impact not only directly on their nutrition levels and the subsequent benefits to immunity and health of receiving adequate nutrition, but also because of the influence diet has on the gut microbiome, and its role in immune function. This includes plenty of vegetables and fruits, and avoiding where possible junk food and sugar. Sufficient proteins are also necessary for the immune system to function properly (1), this may include the intake of eggs, fish, meat, and soya beans which provide complete proteins easily utilised by the body. Enriching a child’s diet with herbs and herbal teas is a simple way to increase the diversity of healthy nutrients they ingest and promote good health.
Nature biodiversity
There is no doubt that spending time in nature is beneficial for health, in part because of the stress-reducing effect it has which can in turn improve immunity, and children are no exception to this. However, there are also even more profound benefits of spending time in nature for the health of children’s immunity.
Observational studies suggest that immune-mediated diseases are more frequent in populations adopting modern urban lifestyles than in populations with a pre-industrial lifestyle (9). One proposal for this is that children living in urban areas receive less exposure to natural environments (such as forests) where they will encounter environmental biodiversity, which is thought to influence the microbiota of the skin and gut.
A study of children in nursery schools covered the concrete yards with forest floor (sod), trees and other forest materials the children could play on and touch. They found that there was high diversity of skin bacteria in the intervention group exposed to more biodiversity, concluding that exposure to diverse environmental microbiota was associated with changes in skin and gut microbiota of children, which was also found to be related to changes in immunes cell levels, specifically cytokine and T-regulatory cells. The study results indicate that exposure to environmental microbial diversity can modulate function of the immune system in children through changes in their microbiome, which suggests that the relatively simple measure of taking children to the forest or letting them play in the mud has the potential to improve their immune function and health (9).
Sleep
Sleep is important for overall health and therefore immunity. Younger children need between 12 – 16 hours of sleep and adolescents 8 – 10 hours. A regular bedtime routine free of screens in at least the 1 – 2hours before bed is helpful for ensuring good sleep (10).
Activity
For health, it is recommended that children are active for one hour per day, which might be playing in the park, or going for a walk (10).
References
- M, Ghobrial RM, Kuchar E, Lewicki S, Kubiak JZ. Development of child immunity in the context of COVID-19 pandemic. Clin Immunol. 2020;217:108510. doi:10.1016/j.clim.2020.108510
- Ogal, M., Johnston, S.L., Klein, P. et al. Echinacea reduces antibiotic usage in children through respiratory tract infection prevention: a randomized, blinded, controlled clinical trial. Eur J Med Res 26, 33 (2021). https://doi.org/10.1186/s40001-021-00499-6
- F, Paparo L, Nocerino R. et al. Specific gut microbiome signatures and the associated pro-inflamatory functions are linked to pediatric allergy and acquisition of immune tolerance. Nat Commun, 12:5958;2021. https://doi.org/10.1038/s41467-021-26266-z
- S.V., Patangia, D.V., Patil, R.H. et al. Factors influencing the gut microbiome in children: from infancy to childhood. J Biosci 44, 49 (2019). https://doi.org/10.1007/s12038-019-9860-z
- Bone, K, The Ultimate Herbal Compendium. Warwick, Queensland: Phytotherapy Press; 2007.
- Echinacea remedy not for children under 12, says MHRA. BBC News website. https://www.bbc.com/news/health-19318309. Accessed 24 August 2022.
- Pizzorno J, Murray M, Joiner-Bey H, The Clinician’s Handbook of Natural Medicine. 2nd ed. St Loius, Missouri: Churchill Livingstone Elsevier; 2008.
- Roslund MI, Puhakka R, Gronroos M, Nurminen N, Oikarinen S, Gazali AM, et al. Biodiversity intervention enhances immune regulation and health-associated commensal microbiota among daycare children. Science Advances. 2020;6:(42). DOI: 10.1126/sciadv.aba2578.
- McCarthy C. Child and Teen Health, Boosting your child’s immune system. Harvard Health Publishing Harvard Medical School. 2021. https://www.health.harvard.edu/blog/boosting-your-childs-immune-system-202110122614. Accessed 24 August, 2022.
