Antibiotic resistance represents a major public health challenge, and is associated with a high mortality rate. While bacteriophages—viruses that kill bacteria—could be a solution for fighting antibiotic-resistant pathogens, various obstacles stand in the way of their clinical development. To overcome them, researchers from Inserm, Université Sorbonne Paris Nord and Université Paris-Cité at the IAME Laboratory, in close collaboration with their counterparts at Institut Pasteur and the Paris Public Hospitals Group (AP-HP), have developed a model to better predict the efficacy of phage therapy and possibly develop more robust clinical trials. Their findings have been published in Cell Reports.