In people of young or middle age, the body's own defences should be perfectly trained and fit for all situations in life. If this is not the case, it is usually due to the lifestyle. But there are also exceptions for younger people - for example in the case of serious operations and certain illnesses.
How do I recognise a weakened immune system?
A common and fairly certain sign of a weakened immune system is an increased susceptibility to infections. If the body's own defences do not function well, bacteria, viruses and pathogens of other species have an easy time.
You often have a cold and catch the flu practically every year? Do gastrointestinal infections also often cause you problems? Such diseases, often dismissed as "banal infections", occur much more frequently in people with immunodeficiency. This is referred to as an acquired or secondary immunodeficiency - in contrast to a congenital (primary) immunodeficiency.
Do you often feel tired and worn out even without a specific infectious disease? Do you often find it difficult to concentrate on your tasks? This can also be due to a weakened immune system.
The most common signs of a weak immune system are
- increased susceptibility to infections (flu-like infection = cold, rhinitis, cough, sore throat, gastrointestinal infections, flu = influenza, fungal infections etc.)
- Infections occur repeatedly after a short time
- Tiredness, fatigue
- Lack of energy, lack of concentration.
Can diseases limit my defences?
How you live and take care of yourself - this plays a big role in the strength of the immune system. However, chronic diseases can also weaken the body's defences, either due to the disease itself or due to the use of medications used for healing/relief. In particular severe chronic diseases can weaken the immune system, e.g.
- bronchial asthma
- chronic bronchitis
- COPD (chronic obstructive pulmonary disease)
- diabetes mellitus.
Infection with the human immunodeficiency virus HIV directly damages the body's immune system. In the final stage, in which the disease is called AIDS, patients are extremely susceptible to infections and inflammatory processes. In people with a healthy immune system, such infections are rare and are usually well parried by the body's own defences. In AIDS patients, they are life-threatening and eventually lead to death.
Cancers that affect the immune cells themselves, such as leukaemia and lymphoma, also severely impair the immune system.
Can medical treatments weaken the immune system?
In the case of various severe diseases, the immune system is artificially suppressed by drugs (immunosuppression). This happens in autoimmune diseases (when the immune system is so disturbed that it turns against its own body), for example rheumatoid arthritis, multiple sclerosis, ulcerative colitis and Crohn's disease. In such cases, immunosuppression is intended to limit the misguided behaviour of the body's defences.
After serious surgery, the immune system may be temporarily weakened. The extent of the impairments depends on the general condition of the patient and the respective post-operative treatment. Usually, the immune system recovers within a few weeks.
After a transplant, patients receive drugs to suppress the body's own defences. This is to prevent the immune system from attacking and rejecting the transplanted organ. Such immunosuppressants usually have to be taken for life.
In the case of cancer, chemotherapy or radiation can weaken the body's own defences. During chemotherapy, the immune system is temporarily damaged depending on the drug used, the amount of the dose and the number of treatments. During radiation therapy (radiotherapy), the cancer cells are weakened so that they die, while the healthy body cells regenerate. If the haematopoietic bone marrow is also irradiated, the immune defence may also be impaired.
How long is the immune system impaired after cancer therapy?
After chemotherapy or radiotherapy, the immune system usually recovers within a few weeks. In elderly patients and those whose immune system is weakened by other factors (general condition, malnutrition, other diseases, etc.) it may take longer.
If you suffer from an immune deficiency due to an illness or treatment (e.g. cancer therapy, chemotherapy, cortisone treatment, etc.), you should always consult the doctor or specialist treating you.
Tests for the immune system
All the symptoms mentioned so far are only hints. If you suspect that your immune system is severely compromised, a doctor can conduct examinations such as the so-called large blood count and have the immune status and other indicator values determined in the laboratory. Essentially, the number of leukocytes (white blood cells) is of interest.
The Corona virus and the immune system
A pandemic poses special challenges for the immune system - and also creates special conditions. One consequence of the Corona waves can already be seen: Many adults have experienced significantly fewer other infections, especially in winter, than in previous years (for the situation in children, see the next section).
For example, the annual flu epidemic was almost completely absent in the 2020/2021 season: In Germany, there were only a few hundred cases of influenza instead of almost 200,000 infections as in the previous year. The Corona virus has also slowed down the 2020/21 flu wave in Switzerland. Even banal colds occurred much less frequently.
This is probably due to protective measures against Covid disease such as distance regulations, wearing masks in public, hygiene measures such as frequent hand washing, "social distance" and working from home. The closure of public facilities - where viruses like to spread, especially in winter - probably also played a role.
But this does not mean that the immune system has become weaker or is working poorly. In adults - with a healthy lifestyle - the immune system is generally so well trained that it is not weakened even by periods of lesser challenge.
The immune system and the Corona vaccination
Vaccinations are a proven protective measure against dangerous viral diseases. The deadly smallpox has been eradicated for 40 years, and the cruel polio is considered to have been largely defeated, at least in Europe. Vaccination does not weaken the immune system. On the contrary, it enables it to form antibodies against invading pathogens, even against those it has not previously known.
Could vaccination with newly developed Covid-19 vaccines, especially the mRNA vaccines, attack the immune system?
No. All vaccines against the Corona virus developed so far are safe. They do not affect the immune system.
A complete vaccination causes the formation of antibodies and specific immune cells. This usually protects you from getting sick on contact with the pathogen.
At most, the efficiency of the vaccines is different.
Since the Corona virus is highly mutable and mutates very quickly, the vaccines cannot provide absolute protection against infection in all cases. Especially in people with pre-existing conditions - e.g. high blood pressure or diabetes - a so-called vaccine breakthrough can occur. However, vaccination usually prevents a severe or even life-threatening course of the disease.
A very recent and positive news: According to a Stanford University study, the number of antibodies increased even more after the second dose of an mRNA vaccine than after the first. Very important: This second vaccination activates parts of the body's defences that previously played only a subordinate role. In particular, the action of the innate immune system is promoted. This can react more quickly to pathogens and offers less specific but broader protection. Especially the number of so-called monocytes, part of innate immunity, was greatly increased. Monocytes form a protective barrier against very different types of viruses. They could increase and broaden the effect of vaccination against variants of the Corona virus.
Is a fit immune system enough to avoid a Corona infection?
No. Whether one is infected with the Corona virus or not does not depend on whether the body's own defences are functioning at their best or are weakened. A fit immune system can, at best, help to better withstand the disease.
The immune system and the microbiome
The microbiome is the term used to describe the totality of all bacteria and viruses that live on and in humans - from the skin to the intestines. Experts know that this microbiome performs very important tasks of the immune system. The defence functions particularly well when the microbiome is diverse - a factor that in turn depends on lifestyle. An unbalanced, unhealthy diet damages it, as do smoking and too little time spent in the fresh air. Loosely speaking, a person who ate mostly fast food during the pandemic did nothing good for their microbiome. The one who started cooking for themselves and also trying something new once in a while did. On the positive side for our microbiome, however, it should be noted that significantly fewer antibiotics were taken during the pandemic. In any case, any person who neglected this defence system during the Corona times should now take care of it - e.g. with food rich in fibre and vegetables.
Weakened immune system in children
With children, especially very small ones, it can be a little different. Infections, which the youngest normally experience in the first three years of life, have become less frequent during the pandemic or have even disappeared altogether. Many parents of small children are no longer familiar with the fever attacks that are otherwise common among the youngest - they occur when an infection challenges the child's still undeveloped immune system.
Basically, it is important that the child's immune system is confronted with germs and learns in this way for the future. This is known, among other things, because excessive hygiene and too intensive protection against pathogens of any kind promote allergies and autoimmune diseases. The immune system needs training partners to practice. The consequences of the pandemic for the youngest are therefore not yet foreseeable.
- Some experts suspect that especially in children who were (and will be) born during the Corona period or shortly before, an important window for training the immune system was missed. An important imprinting phase of the immune system extends from the development of the embryo into the third year of life. We do not yet know what the consequences might be.
- Typical childhood illnesses could be postponed to another age, which may well be problematic: It is known that smaller children cope with e.g. chickenpox and mumps better than older ones.
- Positive: Children in particular rarely (severely) contract Covid. Therefore, for them, contacts in the playground or on the street, with friends and neighbourhood children, even in the day care centre or school, were significantly less restricted than, for example, for older people, despite temporary closures. So they were definitely exposed to pathogens of one kind or another - the immune system has learned.
- Also positive: Missed experiences of the immune system can possibly be made up for by later experiences with germs.
How can I protect and strengthen my immune system?
Immunodeficiency is not a disease in its own, but a condition that promotes the development of other diseases. If you want to keep your immune system fit, you have to take preventive measures and strengthen your defences. The most important points in the programme "making the defences fit" are the decisive lifestyle factors exercise, nutrition and mental hygiene (e.g. joie de vivre, stress reduction, sleep etc.)
You should do something for your immune system if you
- suffer more frequently from minor infections, e.g. you often have a cold, symptoms such as a cough and sore throat
- experience flu (influenza) infections again and again
- catch gastro-intestinal germs very often
- often feel drained of energy
- have trouble concentrating at work
- feel often stressed and/or sleep poorly.
The immune system is one of our most valuable companions through life. It protects us from diseases and infections of various kinds. It is in our own interest to maintain and strengthen it.
Tips for a strong immune system
- Eat well and with variety. Home-cooked meals with a high percentage of fresh foods, vegetables and fruits are best.
- Drink enough (one and a half to two litres of water daily).
- Maintain a healthy body weight.
- Get regular exercise in the fresh air, whatever the weather. But do not overdo it with very strenuous exercise.
- Don’t smoke. If you're still smoking, quit. If you can't do it on your own, get help from your family doctor or a psychotherapist or from smoking cessation courses. Partners, friends and colleagues can also support you, but are often overwhelmed as sole helpers.
- Make sure you get enough restful sleep. Good conditions for a restful sleep are quiet, not overheated bedrooms, a good mattress and pillows and blankets that fit your body size, your preferred sleeping position and your individual need for warmth. If at all possible, do not use the room as a place to work. Neither computers nor irons should be here. The bedroom should be an oasis of relaxation and well-being.
- Try to keep work and/or family pressures and stress in check. Recover regularly and not only during the holidays. Ensure mental hygiene, speak up in conflicts with a partner, boss or colleagues to an understanding counterpart. Pick a form of relaxation exercise that suits you.
- Get vaccinated against infectious diseases. Vaccinations help your immune system fight off infections before they spread through your body.
Healthy nutrition made easy
Why take the trouble to conscientiously pay attention to individual trace elements and vitamins, when a balanced diet contains what your immune system needs and strengthens? In a diverse, colourful and varied mixed diet you will find everything that strengthens your immune system.
- You don't have to eat meatless, but you should make a point of eating plenty of fresh vegetables and fruits. Do not forget about nuts - they contain a lot of valuable substances. Fish provides light proteins and important fatty acids.
- You don't have to cut back strictly on fat, but you should focus on healthy vegetable fats in reasonable amounts: Cold-pressed rapeseed and olive oil for cooking, frying and salads, fruits such as avocado and olives, nuts and seeds. A flake of butter on the vegetables doesn't hurt either.
- Pure sugar, sweets, industrially produced convenience foods, fast food, pastries, snacks and sodas should be avoided as much as possible. But feel free to eat bread, pasta and polenta, rice and risotto, preferably whole grain products - your body converts the complex carbohydrates they contain into the brain food glucose.
An important nutritional principle: A little bit of everything and nothing in excess.
What foods weaken the immune system?
There is no food as such that weakens the body's own defences, neither coffee nor (cow’s) milk and neither salt nor sugar are "bad" per se. What is bad, however, is excess: a piece of cake every day, nibbling chips in front of the TV every evening, drinking alcohol every night - this takes its revenge at some point and not only with several kilos too much. Maintain a healthy weight with the dietary principles listed above, don't smoke and only indulge in the occasional beer or glass of wine and you will stay fit and so will your immune system.
My child doesn't eat vegetables?
Children generally eat what their parents eat and what is made palatable to them. Show your kids that healthy food is fun, let them help out in the kitchen, and don't take "no" for an eternal answer. Of course, a child may refuse an ingredient or dish, but the palate gets used to new things: Bring the rejected food to the table every now and then without pointing it out and let the child try it. Eventually, it'll catch on.
What sport is good for my immune system?
Almost anything - the main thing is that you get moving. Don't overdo it, too much exercise is not healthy either. Do not overexert yourself, neither with the chosen sport nor with the extent. Get into the habit of exercising regularly and in the fresh air, even in wind and weather.
You're having a hard time with this? Start small. For example, start by exercising for half an hour two to three days a week - brisk walking, cycling, jogging. Increase these activities until you are exercising for half an hour to an hour at least five days a week.
It is even easier if you do some family activities together (e.g. bike rides or hikes with your partner and children) or arrange to do sports with friends.
Set goals: In six weeks, I plan to ride my bike four times a week for half an hour. For the next month, I plan to take a hike with the family every weekend. Reward yourself, for example, with a destination that is attractive to you during the hike. The main thing is that you move - regularly and, if possible, outdoors.
However, you should refrain from sporting activity in the case of acute infections.
