In a new paper in Viruses, Sandrine Le Guellec and colleagues describe a preclinical study involving macaques to predict the efficacy of delivery of nebulizer-administered Pseudomonas aeruginosa phages during mechanical ventilation. They found that the lung deposition of viable phage particles ranged from 6% to 26% of the phages loaded in the nebulizer, and that 1 × 10^9 PFU/mL was an efficient dose.