Infection from SARS-CoV-2, the virus responsible for COVID-19, can cause extensive damage to the respiratory system, especially the lungs. No treatments for COVID-19 currently exist, however. Findings from a recent study in human airway cells and in mice suggest that EIDD-2801, an experimental antiviral drug, might be useful in preventing or treating the lung damage associated with COVID-19.

EIDD-2801 is a ribonucleoside analog, a compound that mimics natural ribonucleosides as a means to block viral replication. Previous work demonstrates that EIDD-2801 is effective against several unrelated viruses including influenza, Ebola, and coronaviruses. A key advantage to EIDD-2801 is that it is available in an easy-to-take pill form.

The authors of the study explored the effects of EIDD-2801 on viral replication of SARS-CoV-2 in human epithelial airway cells. They found that the drug inhibited viral replication in a dose-dependent manner. Then they gauged the drug’s effectiveness as a prophylactic. They found that when mice received the drug shortly after being infected, they lost less weight and experienced less lung damage compared to mice that didn’t receive the drug. The degree of protection was dependent upon the timing of drug administration during the course of the disease, with earlier being better.

These findings suggest that EIDD-2801 is effective against COVID-19 respiratory symptoms in mice. Further study in humans is warranted.

• Link to full study.

• Learn more about COVID-19 in this Q&A episode featuring Dr. Rhonda Patrick.