Our bodies have a complex immune system that works hard to fight off germs and bacteria so that we don't get sick. Children that are learning about the immune system may find it difficult to understand simply by reading a textbook. Parents can organize a series of activities to help their children grasp the concept of how our immune systems actually work. Often, all kids need is to be able to see science in motion to really understand it.
Create a wellness poster with images from health magazines. Draw a line down the center of the poster; write "Well" on the right side and "Sick" on the left. Glue pictures in the appropriate column. For example, pictures of vitamins, fruits, vegetables, water and exercise equipment would go on the wellness side. Images of junk food, cigarettes, alcohol and sneezing people would go on the sick side.
Young children can color a picture of a child that is healthy and involved in a healthy practice, such as eating an apple or riding a bike. Then, he can color a child that is ill to demonstrate the affect that germs can have if the immune system isn't able to fight the germs off.
Each day, read your child a visually appealing book that discusses the immune system on a level that she can easily understand. A good place to start is with "Viral Attack," a comic book designed by the Arizona Science Center so that kids can act out the scenes as parents read them aloud (see Resources); it's appropriate for children ages 6 through 12. Another option for children between the ages of 4 and 10 is "Battle With the Bugs: An Imaginative Journey Through the Immune System," by Dr. Heather Manley. This book takes kids on a journey through a little boy's body, to see how the immune system works from the inside out.
Test the house for germs by using a Petri dish with an agar solution on the bottom. Agar, a gelatin made from seaweed, can be purchased at health food stores. Let your budding scientist wipe a cotton swab on any surface in the house and then wipe it on the agar in the Petri dish. Set the dish aside for several days to see how much bacteria grows. Try another version of this experiment by wiping the surfaces in your home with a cleaning solution such as bleach and water. Then test each area for germs by wiping them with cotton swabs and then wiping the swabs in agar solution in a Petri dish. The children should notice that the cleaning solution attacked the bacteria much the same way our immune system attacks germs.
On note cards, place the name of each of the six immune system cells: B cell, killer cell, memory cell, helper T cell, macrophage and cytotoxic T cell. On separate note cards write out the mission of each cell -- how that cell works to keep the body healthy. Mix the cards up and time each child to see how quickly they can match the cell with its mission.
Hold up pictures of items that are either infectious or noninfectious. For example, include images of a mosquito, tear drop, bloody tissue and thermometer. Give the kids a point each time they correctly identify whether the item is infectious or noninfectious.