An oral antiviral developed for COVID‑19 may soon play a role in the fight against Nipah virus, new research suggests.

A joint team from several Chinese institutions including Wuhan Virology Centre has found that VV116, an oral nucleoside prodrug already authorised for COVID‑19 use in some countries, inhibits Nipah virus in laboratory tests and improves survival in an animal model.

The findings, published in the journal Emerging Microbes & Infections and summarised in a statement from the Wuhan Institute of Virology of the Chinese Academy of Sciences, offer a practical lead for a virus that remains a serious regional threat.

Nipah virus is a zoonotic, negative‑sense RNA virus carried naturally by fruit bats of the genus Pteropus. Spillover to humans can occur directly from bats or indirectly via livestock such as pigs and horses. Clinical presentations range from severe respiratory illness to fatal encephalitis. Outbreaks are sporadic but often deadly, with reported case‑fatality rates between about 40% and 70%.

Recent clusters in South Asia, including cases in India’s West Bengal recently, have drawn renewed concern and prompted quarantine of close contacts. The World Health Organization has classified Nipah as a top‑priority regional threat because of its high lethality, broad host range, capacity for human‑to‑human spread in some outbreaks, and lack of licensed vaccines or specific antiviral therapies.

VV116 is a prodrug that converts inside the body to an active nucleoside analogue called X1. Nucleoside analogues act by interrupting viral genome replication, usually through interference with the viral RNA‑dependent RNA polymerase.

In cell culture, VV116 showed low micromolar potency against the Malaysia strain of Nipah virus, with an EC50 of 0.86 µM; its parent nucleoside X1 had an EC50 of roughly 1.8 µM. These values were comparable to remdesivir in the same assays and superior to favipiravir, a control antiviral tested under identical conditions.

Importantly, human phase I pharmacokinetic data from previous trials indicate that an 800 mg oral dose of VV116 yields plasma concentrations of X1 that exceed the levels needed to inhibit the virus in vitro, suggesting therapeutic exposure is achievable in people.

The team moved from laboratory assays to a stringent animal test. Golden Syrian hamsters were challenged with a lethal dose of the Malaysia strain and treated with oral VV116 once daily for 14 days. Two doses were evaluated, 200 mg/kg and 400 mg/kg, and a favipiravir group served as comparator. Treatment began one hour after infection, modelling immediate post‑exposure therapy.

Pharmacokinetic studies in hamsters showed rapid absorption of X1 after oral dosing, with peak blood levels within an hour and half‑lives of about four to six hours. Drug levels in lung and spleen were high and broadly comparable with plasma. Brain concentrations were measurable but roughly 20 times lower than in the lung and spleen; nonetheless, detectable brain exposure corresponded with reductions in viral RNA in brain tissue.

Therapeutic effects were dose‑dependent and meaningful. The higher VV116 dose produced approximately a four‑log reduction in lung viral RNA by day four post‑infection and significant decreases in spleen and brain viral loads. Lung histology in the high‑dose group showed little or no the severe inflammatory damage present in untreated animals. Survival improved. All vehicle‑treated animals succumbed by day 13, whereas 66.7% of hamsters receiving 400 mg/kg VV116 survived to day 21. The lower VV116 dose and favipiravir provided partial protection, with survival rates lower than the high‑dose VV116 group but better than vehicle.

Repurposing a drug that already has clinical use for another disease offers tangible advantages in an emergency. Safety and pharmacokinetic profiles from prior human studies reduce early uncertainty and accelerate the path to clinical testing. An oral formulation is operationally easier to deploy than an intravenous agent.

Oral drugs can be administered in outpatient settings, in rural clinics, or in the field. They can serve as post‑exposure prophylaxis for high‑risk contacts and frontline healthcare workers, or as an early therapeutic option for patients who do not yet require hospitalisation. That practicality matters in regions where Nipah spillover risk is greatest and health systems may be stretched.

Despite encouraging preclinical results, caution is necessary. Animal models are imperfect predictors of human outcomes. Hamsters provide a useful, stringent test bed, but they do not recapitulate all aspects of human disease.

Non‑human primate studies, which more closely parallel human physiology and immune responses, will be necessary before robust claims about clinical effectiveness can be made. The study initiated therapy one hour after infection. That timing models immediate post‑exposure treatment rather than the more typical clinical scenario in which patients seek care after symptom onset, often days after exposure.

Whether VV116 remains effective when treatment begins later requires evaluation. Brain concentrations of the active metabolite were lower than in lung and spleen. Encephalitis determines much of the morbidity and mortality in human Nipah infection; confirmation that drug levels in human central nervous system tissues reach therapeutic thresholds will be needed. The study did not detail the precise molecular interactions between X1 and the Nipah polymerase complex, nor did it assess the potential for viral resistance, drug interactions, or safety in patients with severe, multisystem illness.

Institutional and industry responses reflect both optimism and restraint. The Wuhan Institute of Virology highlighted the research as evidence of VV116’s therapeutic potential, noting the drug’s effect against both Malaysia and Bangladesh strains in vitro and its efficacy in a lethal animal model.

Vigonvita Life Science Co, a collaborator, indicated that preclinical data support further development and that the company will monitor outbreak trends closely, prepared to initiate clinical trials for treatment and post‑exposure prophylaxis if required. Pharmaceutical experts emphasised that preclinical promise must be followed by rigorous clinical trials before the drug can enter practice.

Practical next steps should include testing in non‑human primates, assessments of efficacy when treatment starts at later time points, evaluation across multiple virus strains and exposure routes, mechanistic studies confirming inhibition of the viral polymerase and probing resistance potential, and planning for rapid, ethically designed clinical trials that can be launched during outbreaks. Public‑health authorities and research funders will need to coordinate to ensure that trial protocols, regulatory pathways and logistics are ready to move fast should human cases increase.

Public messaging should balance reassurance with preparedness. Monitoring data referenced by clinicians indicate active, localized Nipah transmission in parts of India, with occasional clustering and hospital‑associated cases. No confirmed human infections have been reported in Malaysia.

The public does not need to panic. Good hygiene, avoiding contact with sick animals or fruit contaminated by bats, and following public‑health guidance remain sensible measures. The emergence of a promising treatment candidate strengthens preparedness. It does not replace the need for surveillance, infection control and community education.

This research matters because it joins laboratory potency, animal efficacy and prior human pharmacokinetic experience into a package that could shorten the path to an actionable therapy for a dangerous virus.

The drug’s oral route increases feasibility in outbreak conditions. The drug’s existing clinical data reduce the time required to move into human trials. The efficacy signal in a lethal animal model gives reason to prioritise more extensive validation. Those factors make VV116 an attractive candidate for accelerated development, provided that steps are taken to confirm safety and effectiveness in humans.

The study marks an important milestone. It is not the finish line. More work remains. Strong preclinical science, careful clinical testing and coordinated public‑health planning will determine whether this promising antiviral becomes a practical tool against a highly lethal, recurring zoonotic threat.

For now, researchers, health authorities and industry have a credible lead that warrants urgent follow‑up, and communities at risk can take cautious comfort that scientific progress is under way to expand the limited arsenal against Nipah virus.