A multi-institutional team of researchers has recently developed a new antiviral candidate that is capable of inhibiting a broad range of highly contagious coronaviruses, including Zoonotic coronaviruses that can cause severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).

The new antiviral candidate, described in a paper published in the journal Science Traditional Medicine, was based on a compound known as GS-5734, which belongs to the class nucleoside analogs and is currently in development as a potential treatment for the Ebola virus disease.

"This compound shows broad activity against a variety of human and animal coronaviruses and represents an exciting potential therapeutic for a family of viruses prone to emergence from animal reservoirs," said Mark Denison, M.D., Craig-Weaver Professor of Pediatrics and professor of Pathology, Microbiology and Immunology at Vanderbilt University School of Medicine, in a press release.

For the study, the researchers used mouse models for SARS. They administered GS-5734 to the mouse models prophylactic (before infection) and early therapeutic (soon after infection). Interestingly, the compound was able to reduce viral load in the lungs and improve respiratory functions in both prophylactic and therapeutic.

Aside from the animal models, GS-5734 was also capable of inhibiting the replication of SARS-coronavirus and MERS-coronavirus in multiple in vitro systems. This include primary human airway epithelial cells, which are the cells infected by respiratory coronaviruses. The compound was also effective against a circulating human coronavirus, bat coronaviruses, and bat coronaviruses that are considered "prepandemic" because they can infect cultured human cells.

So far, there have been no effective antiviral for any known coronavirus. Coronaviruses are a genetically diverse family of viruses that infect birds and mammals, with most coronavirus strains limited to infecting only certain hosts. About 30 percent of common colds in humans were caused by the coronavirus. Despite being previously limited to some species of animals, the coronavirus responsible for SARS and MERS demonstrated their ability to infect other species. SARS and MERS are both severe diseases with high mortality rates, 10 percent and 40 percent, respectively.