Patients may be immunocompromized due to a variety of conditions, including congenital immunodeficiency, human immunodeficiency virus (HIV) infection, leukemia, lymphoma, cancer or therapy with alkylating agents, antimetabolites, radiation therapy, or large amounts of corticosteroids. The level to which the patient is immunocompromised may vary from severe to mild. 

In general, killed or inactivated viruses are not a risk to immunocompromised patients, and should be administered just as they would be to healthy patients. However, the response of an immunocompromised patient is often not as robust as that of a healthy patient, and higher doses or more frequent boosters may be required. 

In general, we may divide immunocompromised patients into 3 groups: those who are immunocompromised due to HIV infection (A), those who are severely immunocompromised not due to HIV infection (B), and patients with limited immune deficiencies due to specific conditions (C).

For people in group A, adults and children who are infected with the HIV virus should not receive live-virus or live-bacteria vaccines. The exception is the MMR vaccine, as several studies have shown limited adverse affect among adults and children who are HIV positive.

People in group B include people who are immunocompromised due to chemotherapy or radiation, or long term steroid use. Live vaccines should not be administered to this group; although patients are three months out from chemotherapy may receive live virus vaccinations. Immunoglobin therapy may be used for these patients.

People in group C must be treated according to their condition, which includes things like renal failure, diabetes, and alcholic cirrhosis. 

Source: http://www.cdc.gov/Mmwr/Preview/Mmwrhtml/00023141.htm