[Epstein-Barr virus infection. Old and new immunological aspects].

EBV infection may have a wide range of clinical consequences: it is often asymptomatic; some cases-generally adolescents-develop the classic "infectious mononucleosis" syndrome; in rare cases the illness takes a severe, fatal course. EBV is also implicated in some geographic areas, in Burkitt' lymphoma and naso-pharyngeal carcinoma. Recent research has enrich our knowledge on the viral genome and the various viral antigen, but some problems are still unsolved.