Hantavirus Vaccine 2026: Clinical Trials, Candidates, and Development Status

As of mid-2026, there is no globally licensed vaccine against Hantavirus Pulmonary Syndrome (HPS) or the New World hantaviruses that cause it. The only approved product — Hantavax, a bivalent inactivated vaccine manufactured in South Korea — targets Hantaan and Seoul viruses (HFRS) and offers no cross-protection against Andes virus (ANDV) or Sin Nombre virus (SNV). However, the 2026 Andes virus outbreak has dramatically accelerated research timelines, regulatory engagement, and funding for multiple hantavirus vaccine candidates now in clinical trials.

This article provides a comprehensive overview of hantavirus vaccine development in 2026: the leading candidates, their clinical trial status, the institutions driving research, realistic timelines for availability, and how PredictHanta markets are pricing the probability of key milestones.

Why a hantavirus vaccine has been so elusive

Hantavirus vaccine development has lagged behind other emerging infectious diseases for several structural reasons:

• Low baseline incidence — prior to 2026, the Americas reported only 200–400 HPS cases per year, making large efficacy trials logistically difficult and commercially unattractive.
• Antigenic diversity — New World hantaviruses (ANDV, SNV, Black Creek Canal, Laguna Negra, Choclo) share only 60–70% glycoprotein homology, complicating the design of a broadly protective immunogen.
• No validated animal model for HPS — Syrian hamsters recapitulate ANDV disease, but the model was only standardized in 2015, delaying preclinical pipelines.
• BSL-4 requirements — live ANDV work requires maximum-containment facilities, limiting the number of labs that can perform challenge studies.
• Regulatory pathway uncertainty — with no prior hantavirus vaccine licensed in the West, sponsors faced unclear endpoints and no precedent for accelerated approval.

The 2026 outbreak has shifted several of these constraints. Case counts are now sufficient for event-driven trials, the FDA has granted Fast Track designation to two candidates, and BARDA has released $180M in emergency funding for hantavirus countermeasures.

Vaccine platform overview

Three major platform technologies dominate the current hantavirus vaccine landscape:

1. DNA vaccines

DNA vaccines encoding the Gn and Gc glycoproteins of hantaviruses have the longest clinical history. The US Army Medical Research Institute of Infectious Diseases (USAMRIID) and the Naval Medical Research Center (NMRC) have been developing DNA-based candidates since the early 2010s.

• pWRG/AND-M (USAMRIID) — a plasmid encoding the full M segment of ANDV, delivered via electroporation. Phase 1 data (published 2022) showed seroconversion in 78% of participants after three doses. A Phase 2 trial enrolling 400 participants across Argentina, Chile, and the US opened in February 2026 under Emergency Use Investigation (EUI) provisions.
• NMRC trivalent DNA vaccine — encodes Gn/Gc from Hantaan, Puumala, and Andes viruses on separate plasmids co-delivered via intramuscular electroporation. Phase 1b completed in 2024 with acceptable safety and neutralizing antibody titers against all three targets. Phase 2 initiated Q1 2026 in South Korea and Chile.

DNA vaccines offer thermostability (no cold chain below 2–8°C), rapid manufacturing scale-up, and the ability to combine multiple antigens. Their main limitation is modest immunogenicity compared to mRNA or viral-vector platforms, typically requiring 3 doses plus electroporation devices.

2. Virus-like particle (VLP) vaccines

VLPs present hantavirus glycoproteins in their native trimeric conformation on a self-assembling nanoparticle scaffold, mimicking the virion surface without containing any genetic material.

• HantaVLP-01 (Sagitta Biologics / Univ. of New Mexico) — a chimeric VLP displaying ANDV Gn head domain on a hepatitis B core scaffold. Preclinical data in hamsters showed 100% protection against lethal ANDV challenge. Phase 1 opened in December 2025 at the University of New Mexico Health Sciences Center; interim safety data (March 2026) showed no serious adverse events and robust IgG responses after two doses.
• GreenVax HV-Quad (GreenVax Inc., South Korea) — a quadrivalent VLP targeting Hantaan, Seoul, Puumala, and ANDV. Uses a plant-based expression system (Nicotiana benthamiana) for rapid production. Phase 1 in South Korea completed enrollment in April 2026.

VLP platforms excel at eliciting conformationally correct antibody responses and have a strong safety profile (no nucleic acid, no replication). Manufacturing complexity and cost per dose remain higher than nucleic-acid platforms.

3. mRNA vaccines

The success of mRNA vaccines against SARS-CoV-2 catalyzed rapid adaptation of the platform to other emerging pathogens, including hantaviruses.

• mRNA-1080 (Moderna) — a lipid-nanoparticle (LNP) encapsulated mRNA encoding a prefusion-stabilized ANDV Gn/Gc heterodimer. Preclinical results (Nature Medicine, January 2026) demonstrated sterilizing immunity in hamsters after a single dose. Phase 1 trial (NCT06891200) opened at Emory University and Hospital Italiano de Buenos Aires in March 2026, with 120 participants across three dose levels.
• BNT-Hanta (BioNTech / Instituto Malbrán) — a self-amplifying RNA (saRNA) candidate encoding ANDV and SNV glycoproteins. The saRNA platform requires lower doses than conventional mRNA, potentially reducing reactogenicity. IND-enabling studies completed Q4 2025; Phase 1 expected to open in Buenos Aires by July 2026.
• CureVac CV-HV-1 — an unmodified mRNA candidate targeting the conserved nucleocapsid protein (NP) to elicit T-cell immunity complementary to glycoprotein-targeting vaccines. Preclinical only as of May 2026, but notable for its pan-hantavirus design rationale.

mRNA vaccines offer the fastest path from sequence to clinic (<90 days), single- or two-dose regimens, and established manufacturing at scale. Reactogenicity management and cold-chain requirements (−20°C for LNP formulations) are the primary operational challenges for deployment in rural South American settings.

Clinical trial status — May 2026

Key research institutions and companies

The hantavirus vaccine field is driven by a mix of government defense labs, academic centers, and biotech/pharma companies:

• USAMRIID (Fort Detrick, MD) — the longest-running hantavirus vaccine program globally. Developed the pWRG DNA platform and maintains BSL-4 challenge capabilities for ANDV.
• Naval Medical Research Center (NMRC) — co-developer of the trivalent DNA vaccine; expertise in military-relevant infectious disease vaccines.
• Moderna (Cambridge, MA) — leveraging COVID-era mRNA manufacturing infrastructure for rapid hantavirus candidate development. Partnered with BARDA under a $95M contract (January 2026).
• BioNTech (Mainz, Germany) — collaborating with Argentina's Instituto Nacional de Enfermedades Infecciosas (INEI-ANLIS' Malbrán') on the saRNA platform, combining German mRNA technology with Argentine clinical infrastructure and patient access.
• University of New Mexico (Albuquerque) — home to the Sagitta Biologics VLP program and one of the few US academic centers with deep hantavirus expertise dating to the 1993 Four Corners outbreak.
• Instituto Malbrán (Buenos Aires) — Argentina's national reference lab for hantavirus; providing clinical trial sites, patient cohorts, and genomic surveillance for multiple vaccine sponsors.
• Korea Green Cross — manufacturer of Hantavax; exploring a next-generation recombinant HFRS vaccine but not currently pursuing HPS indications.
• BARDA (US HHS) — the primary funder of hantavirus countermeasure development, with $180M allocated in the FY2026 supplemental appropriation following the outbreak declaration.

Timeline expectations for vaccine availability

Realistic timelines depend on the regulatory pathway. Two scenarios dominate current planning:

Scenario A: Emergency Use Authorization (EUA)

If the WHO declares a PHEIC and/or the US declares a Public Health Emergency, the FDA can issue an EUA based on Phase 2 immunogenicity data plus animal efficacy (the "Animal Rule" pathway, 21 CFR 314 Subpart I). Under this scenario:

• Q4 2026 – Q1 2027: EUA possible for pWRG/AND-M (DNA) or mRNA-1080 (Moderna), the two candidates furthest along with BARDA support.
• Initial deployment: ring vaccination of contacts, healthcare workers in endemic zones, and military personnel in affected regions.
• Supply constraint: initial production likely limited to 1–5 million doses in the first 6 months.

Scenario B: Standard licensure (BLA)

Without an emergency declaration, sponsors must complete Phase 3 efficacy trials. Given the current case rate in South America, an event-driven Phase 3 could reach its primary endpoint within 12–18 months of enrollment:

• 2027–2028: Phase 3 enrollment and follow-up for lead candidates.
• 2028–2029: BLA submission and FDA review (Priority Review likely given Breakthrough Therapy designation).
• 2029: earliest full licensure under standard pathway.

The PredictHanta market "WHO PHEIC by Dec 31" directly influences which timeline materializes. A PHEIC declaration would compress the EUA pathway by 6–12 months.

Challenges in hantavirus vaccine development

Even with accelerated timelines, several scientific and operational challenges remain:

Immunological challenges

• Correlate of protection unknown — no validated serological threshold (e.g., neutralizing antibody titer) has been established for hantavirus. Trials must rely on clinical endpoints or the Animal Rule.
• T-cell immunity may be critical — survivors of HPS show robust CD8+ T-cell responses against NP and Gn. Vaccines targeting only humoral immunity may be insufficient for durable protection.
• Antibody-dependent enhancement (ADE) concerns — theoretical risk with sub-neutralizing antibodies, though not observed in animal models to date.
• Cross-protection breadth — a vaccine effective against ANDV may not protect against SNV or vice versa, requiring multivalent formulations.

Manufacturing and distribution

• Cold chain in rural Patagonia — mRNA vaccines requiring −20°C storage face logistical barriers in the very regions where ANDV is most prevalent. DNA vaccines (2–8°C) and VLPs have an advantage here.
• Electroporation devices — DNA vaccines require specialized injection devices, adding cost and training requirements at point of care.
• Scale-up timelines — even with pandemic-era manufacturing capacity, retooling mRNA lines from COVID/flu to hantavirus antigens takes 3–6 months.

Regulatory and commercial

• Small market size — even with the 2026 outbreak, the addressable population for routine vaccination is limited to high-risk groups (rural workers, military, travelers), making commercial return uncertain without government procurement guarantees.
• Endpoint selection — FDA and EMA have not published guidance on acceptable primary endpoints for hantavirus vaccine trials. Sponsors are negotiating on a case-by-case basis.
• International coordination — trials spanning Argentina, Chile, the US, and South Korea require harmonized protocols, data-sharing agreements, and regulatory alignment across ANMAT, ISP, FDA, and MFDS.

The 2026 Andes virus outbreak as a catalyst

The 2026 outbreak has fundamentally changed the hantavirus vaccine landscape in several ways:

1. Funding surge — BARDA's $180M allocation, CEPI's $45M rapid-response grant, and Argentina's $20M domestic vaccine fund have collectively tripled available R&D capital compared to 2020–2025.
2. Regulatory acceleration — FDA granted Fast Track designation to pWRG/AND-M and mRNA-1080 in January 2026. Breakthrough Therapy designation is under review for mRNA-1080 based on hamster challenge data.
3. Clinical trial feasibility — with hundreds of cases per month in Argentina and Chile, event-driven efficacy trials are now statistically powered within 12–18 months rather than the 5–7 years previously estimated.
4. Political will — the MV Hondius cruise ship outbreak and subsequent European cases created media pressure and G7 attention, unlocking procurement commitments from GAVI and the Pan American Health Organization (PAHO).
5. WHO R&D Blueprint activation — hantavirus was added to the WHO priority pathogen list in March 2026, enabling access to the Solidarity Trial framework for coordinated Phase 2/3 evaluation.

Monoclonal antibodies and passive immunization

While not vaccines per se, monoclonal antibody (mAb) therapies represent the nearest-term medical countermeasure and complement vaccine development:

• ANDV-mAb-01 (Regeneron / USAMRIID) — a cocktail of two human IgG1 antibodies targeting non-overlapping epitopes on the ANDV Gn glycoprotein. Phase 1 completed in 2025; Phase 2 as post-exposure prophylaxis (PEP) opened in March 2026 in Bariloche and Temuco.
• SNV-nAb (Vanderbilt VUMC) — a broadly neutralizing antibody isolated from a 1993 Four Corners survivor. Cross-neutralizes ANDV at reduced potency. Phase 1 planned for Q3 2026.

Monoclonal antibodies could serve as a bridge therapy — protecting exposed individuals and healthcare workers — while vaccines complete efficacy trials. Their high cost ($2,000–5,000 per treatment course) limits population-level deployment.

How this connects to PredictHanta markets

Vaccine development milestones are directly tradeable signals on PredictHanta:

• WHO PHEIC by Dec 31 — a PHEIC declaration would trigger EUA pathways, compressing vaccine timelines by 6–12 months. Currently trading at elevated probability given the outbreak trajectory.
• Outbreak trajectory markets — case counts directly affect trial enrollment speed and regulatory urgency. Higher case counts paradoxically accelerate vaccine availability.
• Geopolitical spread markets — if ANDV reaches additional countries, multinational regulatory coordination accelerates (as seen with COVID vaccines in 2020).

Traders should monitor ClinicalTrials.gov updates, BARDA press releases, and WHO Emergency Committee meeting schedules as leading indicators. Phase 2 interim readouts (expected Q3–Q4 2026) will be particularly market-moving events.

What comes next

The hantavirus vaccine field in 2026 is at an inflection point comparable to where COVID-19 vaccines stood in mid-2020: multiple platforms racing through early clinical development, unprecedented funding, and regulatory willingness to compress timelines. The key differences are a smaller target population, less manufacturing infrastructure already in place, and the absence of a validated correlate of protection.

The most likely near-term outcome is an EUA for one or two candidates (DNA and/or mRNA) by late 2026 or early 2027, initially deployed to healthcare workers and high-risk populations in Argentina and Chile. Broader availability — including routine vaccination of at-risk populations in the Americas — likely requires full licensure on the 2028–2029 timeline.

PredictHanta will continue tracking vaccine milestones as they intersect with outbreak dynamics and policy decisions. Explore the full market book to trade on your assessment of these timelines, or dive deeper into the hantavirus biology and outbreak timeline that underpin the current research urgency.