Immune system of children
The immune system is not yet fully developed at birth and needs to be trained over the years. Although the foetus has already developed its first antibodies in the womb, this protection is not sufficient, so the unborn child is given antibodies from the mother via the placenta. Particularly in the first weeks after birth, the baby is protected by maternal antigens – known as “nest protection”.
This explains why premature babies in particular are more likely to suffer from infections – fewer antibodies were able to be passed on in the womb.
After birth, the baby's immune system is supported by breastfeeding. Important antibodies are passed on through breast milk, which offer special protection against pathogens that can weaken the mucous membranes. Strengthening the immune system is one of the main reasons for breastfeeding newborns.
In parallel to the nest protection, the baby's body begins to build up its own immune protection – the specific immune system. Since the newborn is now able to produce antibodies itself, the first vaccinations can now also take place.
Only through contact with viruses and the like does the child's immune system learn how to fight which pathogens. A very sterile environment does not protect children – it only makes them more vulnerable at a later stage.
The immune system learns by surviving diseases – the immunological memory grows. Until our immune system is strong enough, small children in particular often suffer from colds. On average, small children have around twelve colds a year, while schoolchildren have an average of only seven.
Immune system in old age
In newborns, the immune system is not yet fully developed, but with increasing age, defences unfortunately weaken. In fact, the immune response in the elderly is delayed, so infections are more likely to occur.
In the bone marrow, the white blood cells, or lymphocytes, are formed, which form an important component of the immune system. In later years, however, the bone marrow is increasingly replaced by fatty tissue – this results in a decreasing number of defence cells and thus a reduced performance of the immune system.
Therefore, the elderly in particular are affected by infections, but not only does the frequency usually increase – the course can also be different. Annual vaccinations are therefore recommended to prevent diseases such as the flu.
The ageing of the immune system can also lead to a reduced breakdown of viruses – altered body cells can no longer be fought so vigorously.
Slowed metabolic processes and more sensitive skin and mucous membranes also lower the body's natural protective barriers.
The good news: a healthy lifestyle has a major effect on our immune system, even in our later years. A varied diet, daily exercise, sufficient sleep and low stress levels are factors with which we can support our immune system even in old age.