VAPERO is a randomized, unblinded, controlled study to measure the impact of a strategy based on the Unyvero® multiplex PCR test on the adjustment of antimicrobial therapy in patients suspected with ventilator-associated or hospital-acquired pneumonia (VAP/HAP) requiring mechanical ventilation. The gold-standard microbiological diagnostic method for pneumonia in the ICU is still culture-based identification and antimicrobial susceptibility testing (AST) despite being more than a hundred years old, with results turnaround time spanning over several days, exposing patients to potentially inappropriate broad-spectrum antimicrobial therapy. The investigators aim to measure the impact of the Unyvero® testing strategy to improve the percentage of patients with VAP or HAP receiving early targeted antimicrobial therapy compared to standard care.