Influenza A Virus

Influenza viruses are thwarted by a drug that targets a viral enzyme. Credit: Dennis Kunkel Microscopy/SPL

Medical research

Meagre ranks of anti-flu drugs look set to grow

A compound thwarts the influenza virus by blocking viral replication.

Large-scale trials of a new compound show that it quickly beats back the influenza virus — results that could admit this compound to the small club of effective antiviral flu drugs.

For the 2017–18 flu season, the US Centers for Disease Control and Prevention endorsed only three antiviral drugs for treating flu. Unlike those treatments, the compound baloxavir inhibits the virus’s machinery for making genetic information that it needs to replicate itself.

Frederick Hayden at the University of Virginia School of Medicine in Charlottesville and his colleagues performed two clinical trials of baloxavir in people with flu. One trial compared baloxavir to a placebo; the second compared the compound to both a placebo and oseltamivir (Tamiflu), a standard antiviral drug.

In both trials, participants’ viral concentrations dropped steeply after one day of treatment with baloxavir. The same decrease took three days to achieve in participants treated with Tamiflu and longer still in participants who took a placebo. Baloxavir did not relieve flu symptoms faster than Tamiflu, but the researchers say that the compound could provide an alternative for people who are unresponsive to other treatments.