🩸 Lassa Fever Vaccine Tracker Dashboard

Updated July 2026. Tracking Lassa fever vaccine development to prevent viral hemorrhagic fever in West Africa. Lassa fever infects an estimated 300,000 people annually with about 5,000 deaths, primarily in Nigeria, Sierra Leone, Guinea, and Liberia. No licensed vaccine exists. Major 2024–2026 progress: IAVI's rVSVΔG-LASV-GPC vaccine — the world's first-ever Phase 2 Lassa vaccine trial — became fully active across Ghana, Liberia, and Nigeria in early 2025, with approximately 612 participants (adults, adolescents, and children aged 2+, including people living with HIV) enrolled in the IAVI C105 study (NCT05868733). Primary completion is estimated December 2026. Phase 1 results published in NEJM showed sustained immune responses in over 100 adults from a single dose, with the vaccine using the same rVSV backbone as the licensed Merck Ebola vaccine (Ervebo). The LEAP4WA consortium — funded by EDCTP and CEPI — is advancing preparations for a Phase 2b trial of rVSVΔG-LASV-GPC in 2026. CEPI has invested in five Lassa vaccine candidates; two remain in active clinical development (IAVI's rVSV and Oxford's ChAdOx1 candidate in Phase 1). This tracker monitors the complete Lassa fever vaccine pipeline.