Early-stage preclinical research on hantavirus vaccine candidates, including mRNA platforms from Moderna and Korea University plus structural designs from University of Texas teams, underpins the 94.5% market-implied odds against approval in 2026. No orthohantavirus vaccine has received FDA, WHO, or broad international licensure outside limited use of older candidates like Hantavax in South Korea, and no Phase 3 efficacy trials are active. Vaccine development timelines typically require years of human testing after promising rodent data, with challenges including low disease incidence limiting field studies and variable strain coverage. New model systems or funding surges could accelerate progress, but current trajectories make 2026 approval improbable.