How to prevent 1.5 yo toddler from flu every week in childcare?

It is common for children below the age of 7 to fall sick easily as their immune systems are still immature and developing. Just sharing what some of my friends did to help boost their children's immune system. One of them brought her son to Yu Guo TCM for children massage. She felt that it helped strengthen his body and has been less susceptible to common cold and flu. Another simply try to introduce more fruits and vegetables. She said that making soup is a good way to provide a balance diet (e.g., chicken soup with vegetables) and to get her children to eat their vegetables. In addition, soup is a good way to ensure that children are well hydrated. Hope this helps!