Lassa fever vaccine use cases and demand: Perspectives from select West African experts.

Lassa fever (LF) is a zoonotic viral hemorrhagic disease endemic to several West African countries. Approximately 300-500,000 cases occur annually across all ages with 10-20% case fatality rates. A LF vaccine is a recognized public health priority, with several candidates entering clinical trials. However, the perspectives of regional experts regarding critical vaccine properties, ideal delivery methods, and priority target populations remain unclear. Using a mixed methods approach with a standardized questionnaire, we individually interviewed 8 West African stakeholders, each with extensive knowledge and experience of LF. They strongly favored the use of a mass, proactive campaign strategy to immunize a wide age range of people in high-risk areas, including pregnant women and health care workers. We estimated that these and other plausible delivery scenarios could result in an initial demand of anywhere from 1 to 100 million doses, with most demand coming from Nigeria. These findings may help inform LF vaccine development and deployment efforts.