Vaccines for Epstein-Barr virus (EBV) could be prophylactic to prevent primary infection and diseases directly caused by EBV, including mononucleosis and posttransplant lymphoproliferative disease. Prophylactic vaccines might also prevent or reduce diseases in which EBV is a cofactor, including multiple sclerosis and other autoimmune disorders, EBV-positive B cell lymphomas, nasopharyngeal carcinoma, and certain gastric carcinomas. Alternatively, EBV vaccines could be therapeutic to treat autoimmune disease and malignancies associated with EBV. In general, prophylactic vaccines focus on induction of antibody to the virus, while therapeutic vaccines focus on inducing virus-specific T cells to kill or control virus-infected cells.