Any scheme for an anti-Epstein-Barr virus (EBV) vaccine will need to be performed in 2 steps: A small scale pilot experiment to prove the carcinogenicity of the virus in relation to African Burkitt''s lymphoma; and a more complicated long-term project, the wide scale vaccine control not only of Burkitt''s lymphoma, but more importantly of nasopharyngeal carcinoma (NPC), with its great significance in terms of numbers involved. Control of Marek''s disease in chickens was shown 6 yr ago when live, apathogenic herpesvirus vaccines were introduced. The applicability of a live virus vaccine to the human situation is doubtful because it is impossible to administer a suspected tumor inducing virus, however attenuated, to man. Even in remote and undeveloped regions, it is possible to successfully mount complicated programs involving considerable numbers. Should the results of such vaccine program indicate that EBV is causally related to African Burkitt''s lymphoma, even in association with cofactors, the case will be strengthened for its consideration as a likely etiologic agent in NPC. If the recent developments and possibilities are considered, it does not seem unrealistic to suggest that planning for the investigation of the many problems ahead would not be premature at the present time.