Development of a vaccine against Epstein‐Barr virus (HBV) is constrained by the latency phenotypes adopted by different EBV‐associated diseases. Over the last few years an immense body of information on the pattern of viral gene expression in EBV‐associated diseases and the rote of cytotoxic T cells in the control of these diseases has accumulated. It would seem reasonable to suggest that emerging technologies are at a level where vaccine trials aimed at controlling infectious mononucleosis, post‐transplant lymphoproliferative disease, nasopharyngeal carcinoma and Hodgkln's disease are justified. On the other hand, a more cautious approach may be required for the development of vaccines or immunotherapeutic strategies against Burkitt's lymphoma.