Host Immunity to Phage Therapy: Is It Time to Worry?

Phage therapy with bacteriophages (viruses that infect bacteria) has undergone a resurgence due to rising antibiotic-resistant infections, particularly among immunocompromised patients. Although immune responses are known to develop against bacteriophages, how rapidly this outcome occurs and what effect it will have on therapeutic efficacy is not clear. Investigators studied samples from a bilateral lung transplant recipient with a multidrug-resistant Pseudomonas aeromonas pneumonia who had received an initial 2-week course of intravenous phage therapy followed by inhaled phage therapy upon relapse. Ultimately, the pneumonia resolved and the patient was discharged.

After the initiation of intravenous phage treatment, the number of activated …