The first is the happiness. Mood has a great influence on immune ability under the combination of complex mental effects. Happiness can improve immunity.
Don't blame the child too much. Children are still young and can't bear heavy mental pressure. Too much punishment will lead to mental disorder and decrease of immunity.
Supplement must get nutrients. Some substances in the body have an impact on the immune system, so the lack of them will lead to the lack of immunity.
physical exercise. Exercise can make people healthier, more beautiful and more immune.
Work and rest are reasonable. Have regular life, let the body get enough rest. Avoid fatigue that can damage your body.
Finally, be optimistic. Don't have a negative spirit. Happiness alone is not enough to build a healthy body, but also a positive outlook on spirit. Immunity will be high.