Viruses are usually associated with causing infections, but some can actually help fight them. Scientists are now working to turn these bacteria-killing viruses into treatments for dangerous infections that no longer respond to conventional antibiotics.

An international team of experts has taken an important step toward making this approach safer and more practical for medical use. Led by the German Society for Infectious Diseases (DGI), the group has developed the first internationally coordinated clinical guidelines for personalized phage therapy, a treatment that uses carefully selected viruses to attack harmful bacteria.

The effort involved 20 professional organizations, 18 international experts, including representatives from regulatory agencies, and two patient advocacy organizations. Together, they established more than 60 recommendations covering how phages should be selected, tested, manufactured, administered, and monitored.…