No Hantavirus vaccine candidate has advanced to Phase 3 clinical trials as of mid-2026, leaving regulatory approval by year-end highly improbable under standard FDA pathways that require extensive safety, immunogenicity, and efficacy data. Existing options like South Korea’s Hantavax target only select Old World strains with modest, short-lived responses and lack cross-protection against New World viruses such as Andes or Sin Nombre. Ongoing work remains early-stage, including Phase 1 DNA vaccines showing neutralizing antibodies in small human cohorts and preclinical mRNA or subunit candidates. A realistic challenge to the current 94.5% “No” consensus would require an unprecedented emergency-use authorization or accelerated review triggered by a major outbreak, though historical timelines indicate such shifts are rare without Operation Warp Speed-level intervention.