There is no vaccine currently available for Lassa fever. Early supportive care, symptomatic treatment, and the anti-viral drug Ribavirin are the main options for treating patients (for more detail see our pages on care and treatment of Lassa fever). The current suggested treatment of Lassa cases using Ribavirin is based on the results of a single study carried out in Sierra Leone in the 1980s. Other studies tested the use of convalescent plasma in treatment but the results were inconclusive.
Research on vaccines for Lassa fever and the treatment of Lassa fever has been ongoing since 1986. There are currently 12 Lassa therapeutic candidates in the pipeline. Difficulties around the development of vaccines and vaccine research have included access to funding, weak health care systems, lack of knowledge about the incidence of the disease (including surveillance or epidemiological data), and the presence of different lineages of the virus in the countries where Lassa fever disease occurs (which might require different kinds of vaccine). The lessons learned during the West African Ebola outbreak, when the global community was unable to deploy vaccines until the epidemic was in its tail despite having had a number of vaccine candidates in the pipeline, galvanized the global health community. The WHO has developed a research and development roadmap for Lassa fever. CEPI, a global partnership which aims to develop vaccines against emerging infectious diseases, recently began preparation of clinical trial sites for Lassa fever in different West African countries.