Can we develop broad-spectrum antiviral drugs to treat multiple viral infections?

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A host of viruses have evolved ingenious ways to cause disease in humans and animals. We have vaccines to prevent viral infections, but only for a few selected viruses. Although antiviral drugs exist, they treat an even smaller number of viral infections. Each of these antiviral drugs targets just a single virus, resulting in the need for a new drug for every virus. New viruses are constantly infecting animals and humans, requiring frequent development of new drugs. Other viruses only infect very few people or animals, resulting in limited commercial interest in developing drugs against them.

On the other hand, each bacteria-killing antibiotic is effective against many different bacteria. As a result, we always have an antibiotic available to treat even new or rare bacterial infections. It would be ideal to also have broad-spectrum antiviral drugs that work against as many viruses as possible. Researchers in Schang’s group are looking for common strategies used by unrelated viruses to enter cells and reproduce. This approach is well-suited to identify viral Achilles’ heels to aid in the development of broad-spectrum antiviral drugs.

Most viruses have a coat of oily lipid molecules called an envelope, which is very similar to a cell membrane. The virus envelope must fuse with the cell membrane to dump the viral contents into the cell. Schang and his group have identified molecules that block this fusion, preventing viral entry and its consequent replication. These molecules are active against a number of viruses that infect humans and companion animals.

A related project also aims to keep viruses out, by preventing them from latching onto sugar molecules on the cell surface. Most viruses latch to one of two different types of sugars, but Schang’s group has discovered a family of molecules that blocks latching to both, thus preventing infection by a number of viruses that infect companion animals and humans.

Schang and his group are finding common principles among many different viral infections, while also bringing to light novel molecules that can be further tailored toward life-saving antiviral drugs. The most advanced of Dr. Schang’s molecules has been optioned by a startup, which is exploring its clinical potential.

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