How do you increase your immunity? I have brocial issues at least 4 times a year?

Wash hands, sleep. After getting a checkup and being sure you don't have an immune problem that needs treatment (such as HIV infection or other immune problem), you can avoid getting sick so often by washing your hands frequently (avoids catching germs), getting enough sleep, having a healthy diet and getting exercise.
Immune Deficient? You may have an immune system that is not functioning to its full potential. Perhaps your body is unable to make adequate antibodies needed to fight infection (common variable immune deficiency). Your white blood cells may lack the ability to kill bacteria (chronic granulomatous disease). Your doctor can help you to identify any potential chinks in your armor.