The deadly MERS virus has been detected in three patients in the United States, and numbers of infected are still growing in the Middle Eastern nations in which it first emerged. Because of the recent emergence of this alarming illness, drugs designed to specifically treat MERS infection are not yet available and are not expected to become available any time soon. Three studies published this week in the journal Antimicrobial Agents and Chemotherapy describe how drugs already approved by the U.S. Food and Drug Administration (FDA) for other uses show promise in inhibiting the replication of MERS virus.

The U.S. Centers for Disease Control and Prevention report that three domestic cases of MERS, or Middle Eastern Respiratory Syndrome, are confirmed. The World Health Organization reports that MERS, first detected in 2012, has to date been confirmed in 536 cases, 145 of which have been fatal. Symptoms of MERS overlap with many common illnesses and include coughing, fever, and shortness of breath. However, unlike those other common illnesses, MERS is deadly for about a quarter of those infected.

One of the new studies reported by U.S. researchers who previously demonstrated that a drug called SSYA10-001 blocks Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) replication documents inhibition of MERS Coronavirus (MERS-CoV) replication. The drug also blocks Mouse Hepatitis Virus and offers proof of principle in targeting multiple coronaviruses with broad-spectrum inhibitors.

In another new report, a team of multi-institutional scientists in Maryland describe the discovery of 27 FDA-approved drugs or compounds in advanced clinical development that exhibit inhibitory effects on both MERS-CoV and SARS-CoV. These were discovered in a screen of a library of 290 compounds.

Finally, researchers in the Netherlands and Belgium report that a screen of a library of 348 FDA-approved drugs yielded four compounds with modest but significant inhibitory effects on MERS-CoV replication. The four compounds, chloroquine, chlorpromazine, loperamide, and lopinavir, may inhibit MERS-CoV replication just enough to allow an immune response to mount.

The findings offer hope in a time of anxiety over the spread and deadliness of MERS in light of no available treatments.