Viruses are surprisingly difficult to kill – most of the drugs and chemicals that do the job are also harmful to human health. But now, scientists have developed a new virucidal substance derived from sugar, making it deadly to a wide range of viruses but safe for us.

The vast majority of existing antiviral treatments don’t actually kill the bugs – they instead slow down their growth or reduce their ability to infect cells. While this can be an effective method of staving off illness, viruses evolve quickly, so they often mutate new defenses against these drugs.

What’s needed are new virucidal treatments that will do away with viruses properly, and ideally work against different types. Now, researchers from the University of Manchester, the University of Geneva (UNIGE) and EPFL have managed to create a promising new virucidal drug.

The team started with molecules called cyclodextrins, which are natural derivatives of glucose. They engineered these molecules to attract viruses, then cling to their surface and tear open their outer membranes, effectively destroying them.

A microscope image of a virus before and after treatment by the antiviral molecules EPFL

The researchers tested the new treatment on several types of viruses, including herpes, HIV, hepatitis C, Zika and respiratory syncytial virus, and saw strong results across the board. The molecules were tested in lab dishes of the viruses and tissue cultures, as well as in mice, and were found to be effective. Importantly they didn’t harm cells in the tissue cultures or the mice, and other tests showed that the viruses weren’t able to mutate resistance to the drug.

“We have successfully engineered a new molecule, which is a modified sugar that shows broad-spectrum antiviral properties,” says Samuel Jones and Valeria Cagno, lead researchers on the study. “The antiviral mechanism is virucidal meaning that viruses struggle to develop resistance. As this is a new type of antiviral and one of the first to ever show broad-spectrum efficacy, it has potential to be a game changer in treating viral infections.”

The team says that this molecule could be useful against viruses that have developed resistance against other treatments, and even future threats similar to the emerging coronavirus. The molecules have been patented and the team is currently setting up a spin-off company in order to bring it to market. The eventual goal is to develop them into ointments, nasal sprays and other treatments.

The research was published in the journal Science Advances.

Source: EPFL