The immunosuppressed traveler.

This article reviews the normal immune response to vaccines. It describes the effect of different immunosuppressive therapies (glucocorticoids, inhibitors of calcineurin and mTOR, azathioprine, mycophenolate acid, methotrexate, depleting and nondepleting monoclonal antibodies, and tumor necrosis factor antagonists) on critical steps in the cellular and humoral immune responses to vaccines. The impact of age-related involution of thymus and bone marrow on the immune reconstitution in allogeneic hematopoietic cell transplant recipients and human immunodeficiency virus is covered. A practical approach to vaccinating and preparing travelers with severe immunosuppression is proposed.