ABSTRACT
Equine infectious anemia virus (EIAV) is a lentivirus related to HIV (human immunodeficiency virus). EIAV causes a persistent infection characterized by recurring febrile episodes associating viremia, fever and thrombocytopenia. Despite a rapid virus replication and antigenic variation, most animals progress from a chronic stage characterized by recurring peaks of viremia and fever to an asymptomatic stage of infection. The understanding of the correlates of this immune control is of great interest in defining vaccine strategies. Research on EIAV over the last five decades has produced some interesting results on natural immunological control of lentivirus replication and disease and on the nature and role of virus variation in persistence and pathogenesis. This review focuses on the most recent results on EIAV biology, replication and control by the host immune response.