The “immune gap” stage in children


A child’s passive immune system is established through the transfer of antibodies from the mother during the last three months of pregnancy and the first six months of breastfeeding. However, as the child grows, this passive immunity  system declines, and from 6 months onwards, children need to develop their own active immunity.

1. What is the immune gap?

The immune system is a protective system that includes many structures and biological processes of the body to protect and fight diseases by recognizing antigens (bacteria, viruses, parasites, cells, foreign cells,…) and prevent their invasion, thereby producing antibodies that destroy them. The body has two immune mechanisms: active and passive. 

The immune system is the body’s system to protect and fight diseases by recognizing invading antigens (bacteria, viruses, parasites, foreign cells, etc.), thereby producing Antibodies that destroy them. 

The mother lays the foundation for the child’s immune system by providing antibodies through the placenta in the last 3 months of pregnancy and the first 6 months of breastfeeding. This is a source of passive immunity for children, helping them adapt to the environment outside the fetus. However, as children develop, this passive immune system declines, and from 6 months onwards, children need to develop their own active immunity. This is a natural process, preparing the body to protect itself against pathogens, marking the transition from passive immunity to active immunity, appearing in the period from 6 months to 3 years of age, known as the “immune gap”.

During the “immune gap” period, children are vulnerable due to the fact that amount of antibodies transmitted from mother to child is significantly reduced while the child’s immune system is still not fully developed. 

At this stage, the amount of antibodies transmitted from mother to child is significantly reduced, while the child’s immune system is not mature, it is gradually developing and learning to fight pathogens through changes as followings:

– Enhances the production of immune cells including B and T lymphocytes, which play an extremely important role in the body’s immune system. These cells are created in the bone marrow and circulate in the blood and lymph tissue, working together to protect the body against foreign agents such as bacteria, viruses and cancer cells. 

– After 6 months of age, the amount of IgG antibodies – the most important type of antibody in protecting children from infectious diseases, transmitted from mother to child gradually decreases. The body begins to produce more antibodies to fight pathogens.

– The immune system begins to remember the pathogens it has encountered in order to fight them effectively in the future, in other words, forming “immune memory””.

2. How dangerous is it for children at the age of “immune gap”?

The immune gap may be a new concept for some parents, but it is the most dangerous stage and greatly affects the child’s health. At this stage, children are at risk of health problems that require special attention from parents.

– As mentioned above, during the “immune gap” period, the passive immunity from mother to baby declines while the child itself has not yet perfected the active immune system to protect itself. Therefore, the body is very sensitive to infectious agents from the outside environment, causing frequent illnesses such as flu, diarrhea, pneumonia, allergies… That is why the frequency and Sickness also lasts longer than usual.

According to statistics from the World Health Organization (WHO), each year there are an estimated 1 billion cases of influenza, including about 250,000 to 500,000 deaths and 3 to 5 million severe cases of seasonal flu. According to the US Centers for Disease Control and Prevention (CDC), influenza is a disease that is at an alarming level with increasingly worse developments, and the number of cases and deaths is constantly increasing. Children under 5 years old, especially children under 2 years old, are at high risk of experiencing serious complications of the flu after being caught.

– At this stage, in addition to the decrease in resistance, there is an increase in children’s contact with the outside environment when they begin to roll over, crawl, walk,… or explore the world by using senses: taste, smell, touch… This is the “golden opportunity” for pathogens to attack the body, making children susceptible to disease. Without proper care and attention, it can lead to a weakened immune system, an underdeveloped digestive system causing poor absorption, stunting and even the risk of poor mental development.  

During the “immune gap” stage, the child’s body is very susceptible to attacks by pathogens, leading to illness  

However, in reality, helping children go through the “immune gap” is simple, if parents understand this stage properly and create good health protection habits for their children. We will state this clearly and in detail in the following section along with useful solutions.

3. Instructions for child care during the “immune gap” period

At the Phase II Immunological Nutrition and Science conference (2022-2024), speaking about the topic on how to care for children during the “immune gap” period, Associate Professor, Dr. Dieu Thuy shared: “A balanced, complete and scientific diet can completely help children have outstanding physical, intellectual and immune development. Strong immunity allow children to prevent diseases caused by viruses, bacteria, and are definitely the foundation for children to develop comprehensively” ,it proves that providing scientific and reasonable nutrition is something mothers need to pay close attention to.

– Breast milk provides all the basic nutrients for a child’s development, especially containing antibodies and beneficial bacteria that help strengthen the child’s immune system. Therefore, the only way to keep children healthy and less susceptible to infections is to breastfeed exclusively for the first 6 months of life. Besides, mothers also need to eat all 4 groups of nutrients to maintain enough quantity and quality of milk for their babies.

In cases where breast milk is not guaranteed, such as postpartum infection or loss of milk and the baby must be fed with formula, it is necessary to choose a type that provides antibodies equivalent to breast milk to provide the baby with enough passive immunity.

In the first 6 months of life, it’s necessary for mothers to get food that contain all 4 groups of nutrients to maintain enough quantity and quality of milk for their baby

– Children from 6 months to 3 years old are in the “immune gap” phase and also entering the weaning phase, which means that the active immune system is very weak and the microflora is imbalanced. Intestinal bacteria cause diarrhea, respiratory diseases, etc. to increase. Therefore, at this important stage, in addition to maintaining breastfeeding, it is necessary to form healthy eating habits for children with foods that increase resistance such as green vegetables and fruits containing vitamin C (kale, peas, citrus,..), lean meat, fish containing omega 3 fats, yogurt,…

In addition, clean personal hygiene for children and a clean surrounding environment are also points that need to be emphasized in child care at this stage. Since skin, respiratory diseases, and others are largely affected by the living environment: water source, air, surfaces in contact with the child. Parents need to be careful to wash children’s hands before eating and after going to the toilet, always wear clean clothes, and the space needs to be airy and clean to minimize pathogens for children.

Clean personal hygiene is also an important point of focus to take care of your child’s immune system

Besides, strengthening children’s immune system by fully and properly vaccinating as recommended by the Ministry of Health is also an effective method to provide children with disease-preventing antibodies and a healthy immune system. Children from 0 to 24 months old need to be vaccinated with vaccines: hepatitis B, tuberculosis, diphtheria, tetanus, pertussis, polio, pneumonia, meningitis, mumps, rubella…

Below is the expanded vaccination schedule of the Ministry of Health. Parents need to pay attention to vaccinate their children correctly and sufficiently.

Expanded vaccination schedule from Ho Chi Minh City Department of Health, updated January 9, 2024  

In particular, use appropriate preventive measures to effectively protect children from pathogens such as supplementing IgG antibodies to activate the complement system, bind antigens, and mobilize immune cells. A representative of the National Children’s Hospital shared in a seminar on immunonutrition organized by the Ministry of Health in collaboration with Vitadairy: “Children with IgG antibody deficiency cause a weak immune system, so they often catch minor illness and get Infection, that leads to the use of antibiotics. Using antibiotics regularly can cause an imbalance in the intestinal microflora, causing several diseases, risking side effects, and easily causing drug resistance”.

Many parents still believe that by limiting their children’s exposure to the outside environment, they will not get sick, and this is absolutely not true. On the contrary, it brings more risk of infection in the future, because the child’s immune memory is limited. Therefore, for an immature immune system, increasing resistance is very important and is the only meaningful way to prevent infectious diseases for children. Currently, the application of immunonutrition in daily child health care is also one of the topics that is of great interest in development.

Nutricare Medical Nutrition Institute – USA (NMNI-USA) in cooperation with Nutricare has successfully researched and produced the new ColosCare 24h product, which is a nutritional solution of outstanding quality according to US standards and suitable for physical condition of Vietnamese, to care for and improve the health of millions of children. The product not only provides an exceptionally high 1200mg IgG antibody content from 24-hour Colostrum imported from the US, but also supplements essential nutrients to help children develop healthily. In particular, IgG (Immunoglobulin G) accounts for about 75% of antibodies in the body. With the ability to strongly bind to pathogens such as bacteria, viruses or fungi, IgG antibodies help control infections in the body, strengthening the child’s passive immune system. When an antigen enters the body, IgG will immediately mark it while waiting for the body’s immune response to be formed, thereby helping to protect the body from the dangers of infectious diseases.

Daily use of ColosCare 24h, children also improve their digestive condition, thanks to the addition of 10 billion beneficial bacteria and HMO to help limit the entry of disease-causing bacteria and viruses into the digestive system, supporting balance of intestinal microflora. ColosCare 24h also contains fiber (FOS/ Inullin) to help reduce diarrhea and constipation in children.

High-quality protein supplement with more than 56 essential nutrients, helping children gain weight healthily and keep up with growth momentum. Together with Calcium and Vitamin D3 with an appropriate Calcium/Phosphorus ratio, supporting the development of the child’s musculoskeletal system and height.

The “Immune Gap” period is a period that any infants have to go through. Parents need to pay attention to improving knowledge and awareness to care for and supplement their children with adequate nutrients, stable sleep and a guaranteed living environment to build a healthy immune system for their children during this period. Let’s get through this period together for a healthier and comprehensive growth of kids.





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