In 2010, Lilli Holst, an undergraduate student at the University of KwaZulu-Natal in South Africa, took part in a project designed to encourage students to find phages. She decided to look in her parents’ compost bin, among other places. A scraping from the underside of a rotting eggplant turned out to contain a phage that was entirely new to science. She called it Muddy.

This phage was found to be able to kill a type of bacteria that can cause particularly nasty diseases. When, almost a decade later, a teenager in London came down with an aggressive, multi-drug-resistant infection following a double lung transplant, doctors gave her a 1% chance of survival. In a last-ditch attempt to save her life, doctors injected her with Muddy, along with two other genetically engineered phages. She began to recover within days and left the hospital a few months later. Muddy has been used to treat over a dozen people in the years since, as I learned in Tom Ireland’s forthcoming book The Good Virus.

Finding the right phage for the job won’t always be straightforward. But scientists are working on alternatives. We might be able to engineer phages, for example, providing them with the genes they need to infect the specific bacteria we want to kill. It might also be easier to make use of the chemicals phages make, rather than the viruses themselves. Phages make enzymes that rip holes in the walls of bacterial cells, bursting them open. We might be able to treat people with those specific enzymes, says James.

Now it seems the time is right for phages to make a return to the spotlight. Antimicrobial resistance is on the rise; it already plays a part in millions of deaths every year. In the UK, an ongoing government inquiry is exploring whether phage research should get more state funding. Over 30 active clinical trials of phage therapies are listed at a US-run trial registry. And Ireland’s book making the case for phages is out this summer.

Once research does make more headway, there’s another challenge to overcome. The idea of intentionally putting viruses into your body is not a particularly appealing one for most people.

Having said that, bacteria have benefited from great PR in recent years. Most of us know the benefits of a healthy gut microbiome, and many people happily chug down bottles of bacteria they buy in supermarkets. Can viruses win us over too?

“We need to stop being so afraid of phages and see what they can do for us,” says James.