evere immunosuppression can be the result of congenital immunodeficiency, HIV infection, leukemia, lymphoma, generalized malignancy or therapy with alkylating agents, antimetabolites, radiation, or a high dose, prolonged course of corticosteroids. The degree to which a person is immunocompromised should be determined by a physician. Severe complications have followed vaccination with live-virus vaccines and live bacterial vaccines among immunocompromised patients (146--153). These patients should not receive live vaccines except in certain circumstances that are noted in the following paragraphs. MMR vaccine viruses are not transmitted to contacts, and transmission of varicella vaccine virus is rare (6,138). MMR and varicella vaccines should be administered to susceptible household and other close contacts of immunocompromised patients when indicated.