Baseline mapping of Lassa fever virology, epidemiology and vaccine research and development.

Lassa fever (LF) is a zoonotic disease associated with acute and potentially fatal hemorrhagic illness caused by the Lassa virus (LASV), a member of the family . It is generally assumed that a single infection with LASV will produce life-long protective immunity. This suggests that protective immunity induced by vaccination is an achievable goal and that cell-mediated immunity may play a more important role in protection, at least following natural infection.