There are many benefits to children attending preschool, daycare, or regular school, including stimulation, education, and social development. The immaturity of their immune systems, however, makes children more susceptible to common colds, the flu, and other viruses.

An average child gets sick 6 to 12 times per year with colds or influenza, which commonly cause a runny nose, fever, and cough. These viral infections usually resolve within seven to ten days, but they often mean absence from daycare and work for children and parents, respectively.

The immune system

The immune system is responsible for protecting the body from bacteria, viruses, fungi, and parasites. As part of the body’s immune system, multiple tissues and cells cooperate to combat infections and keep you healthy.

How does the immune system work?

A person’s immune system is composed of two main parts, the innate immune system and the adaptive immune system.

The innate immune system

Your innate immune system is your first line of defense against infection. It is inherited and active from birth. The innate immune system includes the skin, the mucous membranes that line the mouth, nose, and digestive tract, as well as the gut microbiota and other general barriers to infection. In addition to detecting pathogens, the innate system also includes chemical signals that produce inflammation and fever responses, as well as mobilizing protective cells and other chemical defenses.

The adaptive immune system

In contrast, the role of the adaptive immune system is to create a targeted defence against specific infections. The adaptive immune system produces antibodies that recognize and neutralize individual pathogens or tag them for destruction. Furthermore, memory cells circulate for months or years after an infection ends, so the body can respond quickly if the pathogen returns.

Children's immune system

A child’s adaptive immune system develops with age and through exposure to a variety of infections. Your child's gut plays an important role in their immune health since many new and potentially dangerous microbes and viruses enter the body through the digestive tract. Most of the body’s immune cells are located in the gut, and cells line the small intestine and secrete huge numbers of antibodies. The gut microbiota helps train the adaptive immune system to distinguish between pathogens, beneficial microbes, and the body’s own cells.

How the immune system develops with age

Babies’ immune systems aren’t fully mature until around two or three months of age, making them especially prone to bacterial and viral infections. During the first weeks of life, the fetus is protected from infections by antibodies received from the mother through the placenta. Breastmilk also delivers protective antibodies that can help prevent allergies.

Parents can help protect their baby early on by asking visitors to wash their hands before holding their baby and limiting exposure to people outside the family during the first six months. In order to develop a healthy and diverse gut microbiota, babies need exposure to harmless bacteria during their first three years of life. Bacteria help the immune system identify pathogens and provide a barrier against infections.

How to keep your child’s immune system strong

While occasional colds and cases of the flu are inevitable, there are several ways you can strengthen your child’s immune system.

Eating a varied diet that is low in fat but rich in fruits, vegetables and whole grains helps keep the body and the immune system healthy. A high-fibre diet also feeds the gut microbiota. Additionally, getting adequate amounts of vitamins and minerals ensures that the immune system can produce the cells, antibodies and other molecules needed to fight disease.

Sleep recommendations*

To maintain a healthy immune system, children need plenty of sleep. A lack of sleep can interfere with the production of immune signaling molecules called cytokines that help fight infections.

How much sleep does my child need?

  • Infants 0 to 3 months old, 14 to 17 hours per day
  • Infants 4 to 11 months old, 12 to 16 hours per day
  • Toddlers 1 to 2 years, 11 to 14 hours per day
  • Children 3 to 5 years, 10 to 13 hours per day
  • Children 6 to 12 years, 9 to 12 hours per day*
  • Teenagers 13 to 18 years, 8 to 10 hours per day**

* The World Health Organization
**The American Academy of Sleep Medicine

Strengthen your child’s immune system from the inside

With 70-80% of a child’s immune system located in the gut, taking care of your child’s digestion can help keep him or her healthy. Furthermore, a healthy microbiota helps reduce infection risk.

The importance of vitamin D

Vitamin D is needed for normal growth and bone development in children and is essential for a strong and well-functioning immune system. Vitamin D is important throughout life but is especially important for growing infants and children.

Minimising the spread of infections

There are many ways to reduce the spread of infections, keep your family healthy and minimise sick days. Here are just a few:

  • Make sure both you and your child wash your hands frequently with soap and water, especially when coming home from daycare, work and when using public transportation.
  • Avoid sharing the same towel.
  • Avoid crowds during the cold and flu season.
  • Teach your child to sneeze or cough in a tissue or the crook of the elbow instead of their hands.
  • Let your child stay home if he or she is feeling sick.