This is a way to make the body's immune system
weak so it is less able to fight infection or disease. It also makes the body less likely to reject a transplant. Sometimes, if you've had a transplant, your doctor may use special drugs to weaken your immune system. At other times, it's harmful to have a weak immune system. This could happen as a side effect of treatment (like from chemotherapy
). Or it can be a part of a disease, like AIDS.