It’s the largest ever set of published case studies for therapy using bacteria-killing viruses known as bacteriophages, providing unprecedented detail on their use to treat dire infections while laying the groundwork for a future clinical trial.

Each patient treated in the study was infected with one or more strains of Mycobacterium, a group of bacteria that can cause deadly, treatment-resistant infections in those with compromised immune systems or with the lung disorder cystic fibrosis. In 2019, Hatfull led a team showing the first successful use of phages to treat one of these infections.