A broad-spectrum antiviral targeting positive-strand RNA viruses

What is it about?

Positive-strand RNA viruses are responsible for several diseases of varying severity, including dengue, Zika, yellow fever, Japanese encephalitis, West Nile fever, Chikungunya, COVID-19, and the common cold. We discovered and characterized a drug candidate that functions as a broad-spectrum antiviral that targets positive-strand RNA viruses, inhibiting viral replication, both in cell cultures and mice models. The drug candidate, 2-thiouridine, is an analog of the nucleoside uridine. Our results indicate that it could open a new frontier in the treatment and prevention of these diseases.

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Photo by CDC on Unsplash

Photo by CDC on Unsplash

Why is it important?

Diseases caused by positive-strand RNA viruses vary in range and severity, from SARS-CoV-2 and its variants, which caused the COVID-19 pandemic, to the rhinoviruses and coronaviruses that cause the common cold. Most treatments for these diseases encompass prophylactic measures—such as vaccines for polio, yellow fever and SARS-CoV-2, or physical prophylaxis, preventing contact between infected individuals and the sources of infection—and symptomatic treatments—treating the symptoms of disease in patients as their immune system fights the virus. Currently, there are no broad-spectrum antiviral that target positive-strand RNA viruses. Our discovery of the antiviral activity of 2-thiouridine potentially opens a new avenue for the treatment of diseases caused by these viruses. 2-thiouridine is straightforward and economical to synthesize, and we did not observe any mutagenic or toxic effects in mice at therapeutic concentrations. Should it clear clinical trials, wide adoption of this drug could substantially reduce the impact of diseases caused by positive-strand RNA viruses.