Much Needed Incidence Studies in Support of Lassa Fever Vaccine Development

An improved understanding of Lassa virus (LASV) seroprevalence and incidence is critical for proper design of LASV vaccine studies in humans. The current understanding of LASV epidemiology and circulating LASV genotypes is limited and based on small studies conducted several decades ago. The lead applicant has significant experience with large-scale epidemiology studies, and the participating investigators maintain a strong presence in Sierra Leone with extensive experience with Lassa field studies, including cross sectional studies and advanced LASV clinical laboratory capacity. The cross-sectional visits and surveillance for Lassa fever cases is conducted by teams of outreach workers, and the overall project team is well-versed in epidemiological survey methods, questionnaire administration, informed consent and collection of blood in community settings. We are seeking Wellcome Trust funding to determine incidence and genotypes of LASV in various hotspots in Sierra Leone to inform rationale vaccine trial design and trial site selection. To this end, we propose enrolling 8,000 volunteers from 40 villages (20 of which have participated in the initial cross sectional study and 20 are new study villages) for two visits to determine LASV incidence. Support for epidemiological research will strengthen our partner sites and develop local investigators' capacity to conduct clinical trials.