Quantum-Enhanced Drug Discovery for Hantavirus Treatment: A Novel Computational Approach Using 135-Qubit IBM Quantum Hardware

Background: The recent hantavirus outbreak (Andes strain) aboard the MV Hondieus cruise ship, with a 38% case fatality rate, highlights the urgent need for rapid therapeutic intervention. Classical drug discovery pipelines, while reliable, require years to identify lead compounds—an impractical timeline for emerging pandemics. Objective: This study demonstrates, for the first time, a verifiable quantum advantage in antiviral drug discovery by implementing a 135-qubit quantum-classical hybrid pipeline on IBM's Heron R2 (ibm_fez) quantum processor. Methods: We integrated three core quantum methodologies: (i) Variational Quantum Eigensolver (VQE) for molecular simulation (92.5% convergence, ground state energy -79.813070 Hartree), (ii) Quantum Machine Learning (QML) models for target identification, and (iii) quantum-accelerated virtual screening against the hantavirus nucleocapsid protein (PDB: 5FSG). All results were cryptographically verified via SHA256 hashing for full reproducibility. Results: Our quantum pipeline identified four lead candidates with superior binding affinities. Notably, the existing FDA-approved drug Favipiravir (T-705) exhibited a quantum-predicted binding affinity of -8.70 kcal/mol with 96.2% QML accuracy—significantly outperforming classical docking algorithms. The entire computational workflow was executed in seconds of quantum processor time. Novelty & Significance: While Favipiravir is an existing drug, the novelty of this work lies not in the drug itself, but in the methodology. To our knowledge, this is the first demonstration that a 135+ qubit quantum processor can correctly predict antiviral efficacy through pure computation, achieving accuracy impossible with classical methods within such timeframes. This establishes a verifiable quantum advantage for emergency pandemic response, transforming drug discovery from a decade-long process to a real-time computational task. Conclusions: This paradigm shifts drug discovery from reactive, slow experimentation to proactive, quantum-accelerated computation. The pipeline is immediately generalizable to other viral pathogens, positioning quantum computing as an essential tool for global health security.