”Nest protection” is the transfer of maternal immune cells to the baby, providing it with the mother’s immune system a few weeks after birth. During this time, the baby builds its first immune cells of its own.
What is nest protection?
”Nest protection” is the transfer of maternal immune cells to the baby. This happens weeks before he or she is born, as immune cells are given from the mother to the baby through the placenta. The immune system is formed through experience. Experience means that a person must have had contact with certain germs in order to become immune to them. A large part of building a healthy immune system is done by vaccinations, while other immune cells only need time after birth. If a fetus were to build up its own immune system before birth, it is possible that its mother’s body would recognize it as foreign and subsequently reject it. Furthermore, it does not yet need its own immune system in the womb, because the mother’s immune protection is sufficient for both. After birth, the baby is initially exposed and comes into contact with a range of everyday germs. Without any protection, it could die from the slightest cold. To give it time to mature its own immune system, it receives immune cells from its mother. This happens weeks before it is born, when they are passed from the mother to the child through the placenta. For example, if the mother has been vaccinated against measles, the baby will also have some protection against it for a few weeks. Nest protection lasts about three to six months of life, depending on the pathogen. In breastfed babies, it lasts longer because the colostrum (the mother’s first milk) gives the baby IgA immune cells that protect against intestinal diseases, among other things. During this time, the baby can be vaccinated because nest protection weakens before these first weeks and months of life.
Function and task
In the womb, the baby cannot and does not need to develop its own immune system. It could not even protect itself independently against many pathogens, since it has never come into contact with them. Nevertheless, it will be exposed to germs immediately after birth and cannot come into the world without any immunity – or would not survive for long. For this reason, passive immunization happens in the last weeks before birth: IgG type immune cells from the mother are transferred to the baby through the placenta. IgG cells emerge about 6 weeks after infection and provide lasting immune protection. Thus, they are more than a rapid immune response. The type of nest protection depends on the mother’s immune system. For example, it provides minor protection against colds if the mother had a cold a short time ago. Vaccinated mothers give their babies antibodies as nest protection, including against measles, mumps and rubella. These antibodies are even more effective if they have had the corresponding disease themselves in childhood, but a vaccination of the mother also has a noticeable effect. The nest protection continues during breastfeeding: especially in the colostrum the baby receives another portion of IgA immune cells, which now have an effect on the intestine. Children who continue to be breastfed, especially in the first period of life, benefit from nest protection longer than bottle-fed children, which is one of the reasons why breastfeeding is so recommended. From the first year of life at the latest, the nest protection provided by the mother has completely disappeared, but during this time the baby has also had its own experiences with pathogens and has formed its own first immune cells. If, on the other hand, it has had no contact with the pathogen, it loses the maternal immune protection and must be vaccinated itself to be protected again.
Illnesses and diseases
The extent of nest protection depends on the mother’s immunity and whether the baby is breastfed. For example, a woman who previously had measles herself will pass on stronger nest protection against it to her baby than if she is only vaccinated. Nevertheless, a vaccination also represents a valuable nest protection for the baby – unless the mother’s immunity is no longer given and the vaccination would have to be renewed. At best, it should be checked before pregnancy by means of a blood count whether the woman has all the necessary vaccinations, since it may be too late for the vaccination during pregnancy and the baby’s nest protection would thus be limited. When vaccinating the baby later, it is important to consider how long the nest protection by the mother lasts after birth.Therefore, it does not make sense to vaccinate a baby in the first days of life, because if the nest protection were still present, it would neutralize the vaccination and it would be in vain. That is why pediatricians wait several weeks and months before scheduling the appointment, depending on the type of vaccination. Breastfed infants receive further immune protection through their mother’s milk, especially against intestinal diseases. Bottle-fed infants receive comparable nutrients, but no continuation of nest protection, because bottle-feeding cannot contain immune cells. In addition, any infection of the baby should be taken seriously, as there is no nest protection against some pathogens, such as that of tetanus (Clostridium_tetani), and frequent illnesses may indicate a serious immune deficiency of the baby. A pediatrician can clarify the suspicion.
