Protective and pathogenetic role of T cells in murine malaria: Malaria is characterized by two very distinct phases both of which with a unique interaction with immune system of the host. The liver phase is immunologically silent i.e. no massive induction of the immune system occurs and no pathology is associated with this stage. However, during the liver stage CD8+ T cells that recognize malaria antigen on hepatocytes can mediate protection. Thus current vaccine strategies are concentrating on this stage. A major problem is the short duration of the liver stage. Therefore a vaccine-induced response must induce CD8+ T cells that persist in the liver and produce cytokines immediately after antigen encounter. This problem might be solved by using novel vaccine strategies that efficiently induce T effector/memory cells, which are known to persist in peripheral organs.