Flu viruses are made to move through mucus

Proteins on the outside of influenza A viruses are key to breaching our bodies’ mucus barriers

Kateryna Kon/Science Photo Library

Before viruses can infect cells, they must first get to them, often by traversing layers of the body’s protective mucus. Understanding how evolution optimised the influenza A virus for this slimy task could help us create new antiviral drugs.

If you just dropped an influenza A virus into mucus, natural diffusion would never carry it to cells fast enough to cause an infection, says Siddhansh Agarwal at the University of California, Berkeley. Influenza A viruses – the only influenza…