To boost a child's immune system, focus on key factors like a balanced diet, regular exercise, sufficient sleep, good hygiene practices, and reducing stress. A nutritious diet with fruits, vegetables, whole grains, and lean proteins provides essential nutrients for immune function is crucial in building a child's immune system. Also, encourage physical activity to boost children's immune system. Ensure enough sleep for the body to restore and regenerate. Promote good hygiene habits to prevent infections. Create a supportive environment to minimize stress. By considering these factors, you can effectively boost and strengthen a child's immune system, supporting their overall health and well-being.