Lassa fever is an acute viral hemorrhagic illness that occurs in West Africa, with the Lassa virus transmitted to humans via contact with food or household items contaminated with rodent urine or feces. The disease is known to be endemic in several West African countries, including Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, and Nigeria. It is estimated that there are between 100,000 and 300,000 cases of Lassa fever each year in West Africa, resulting in approximately 5,000 deaths. The high mortality rate of Lassa fever tears apart communities, as stigmatization and discrimination are frequent against infected individuals, healthcare staff, and disease survivors.

Despite the significant impact of Lassa fever, there are currently no vaccines or antiviral drugs approved for the disease. Several vaccine candidates have been under development since 2005, but most require multiple injections and can take up to four weeks to become effective.  To better prepare and combat Lassa fever, the World Health Organization has prioritized the development of countermeasures, including diagnostics, therapeutics, and vaccines. Safe and effective solutions are urgently needed in endemic areas.