What is the immune system and what does it do
The immune system is made of many types of organs and cells specialised in fighting germs. There are three lines of defence within the immune system which are vital to protect our body from infections.
The first line of defence comprises of the skin, mucus layer, saliva, tears, and sweat. The skin act as a barrier against germs and prevents them from entering the body. The mucus layer produces mucus which helps to trap germs and, the saliva, tears, sweat contain a type of chemical called lysozyme, which kills germs. (1-3)
The second line of defence comprise of a group of white blood cells specialize in detecting and destroying pathogens. When a pathogen is detected, other white blood cells are alerted of the pathogen’s presence and an inflammatory response is activated. This causes fever, swelling, redness, and pain. These responses are important to destroy the pathogens and prevent them from reproducing. (1-3)
The third line of defence is activated to train other immune cells to recognized and attack the pathogen. Some immune cells are trained to remember and prepare for the next attack by the same pathogen. These are called memory cells. Besides that, antibodies are also produced and this helps in the elimination of the pathogens. (1-3)
How do babies develop their immune system
- The placenta
During pregnancy, antibodies are shared between the mother and the fetus via the placenta. More antibodies crossover to the fetus as the pregnancy advances to the third trimester, which is the last 3 months of the pregnancy. (4) This helps babies to develop their immune system and protects them from infections when they are born.
Breast milk are rich in immune cells and antibodies which protects the baby from infections. Colostrum, which is milk produced during the first few days after birth, contains the highest amount of antibodies. Besides that, breast milk are also rich in nutrients essential for the growth and development of the baby. (4,5) This is why it is important to practice exclusive breastfeeding for at least 6 months after birth. (6)
- Adequate nutrition
Adequate nutrition is also essential as nutrients such as protein, vitamins, and minerals are important for the growth and development of the immune cells. This starts during the pre-conception stage, which is the stage before conceiving. The nutritional status of the mother is crucial as it can very much affect the development of the baby especially the immune system. (5)
Vaccines are important to ensure the baby is protected from certain pathogens that can cause serious illness such as tuberculosis (TB), polio and hepatitis B. Vaccines contain antigens, a small part or an inactive form of the pathogen, which can initiate an immune response but doesn’t not cause harm to the body. (4,7) This allows the memory cells to remember and prepare for the actual pathogen’s attack.
- How does the immune system work? [Internet]. NCBI. 2020 [cited 03November 2022]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279364/
- Immune system explained – Better Health Channel [Internet]. Betterhealth.vic.gov.au. [cited 03November 2022]. Available from: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/immune-system
- Macdonald K. The Immune Response [Internet]. Let’s Talk Science. 2019 [ cited 03November 2022]. Available from: https://letstalkscience.ca/educational-resources/stem-in-context/immune-response
- The Children’s Hospital of Philadelphia. Development of the immune system [Internet]. Children’s Hospital of Philadelphia. The Children’s Hospital of Philadelphia; 2019 [cited 03November 2022]. Available from: https://www.chop.edu/centers-programs/vaccine-education-center/human-immune-system/development-immune-system
- Pai UA, Chandrasekhar P, Carvalho RS, Kumar S. The role of nutrition in immunity in infants and toddlers: An expert panel opinion. Clinical Epidemiology and Global Health. 2018;6(4):155–9.
- Malaysian Dietary Guidelines. Kuala Lumpur: National Coordinating Committee on Food and Nutrition, Ministry of Health Malaysia; 2010.
- How do vaccines work? [Internet]. World Health Organization. World Health Organization; [cited 03November 2022]. Available from: https://www.who.int/news-room/feature-stories/detail/how-do-vaccines-work?gclid=CjwKCAjwzY2bBhB6EiwAPpUpZj2Xs_Y2z7Aasg_tZ1JQLewnGHNiKRuuC2E0eiOxkfIQgkSt0G8emxoCA80QAvD_BwE