Vallés et al2 acknowledged that the main risk of implementing widespread prophylactic antibiotics in the ICU is the emergence of antibiotic-resistant pathogens. Although the choice of antibiotic in this study covers the organisms commonly colonizing sites of potential inoculum before admission to the hospital, this cannot be assumed for all patient groups. The oropharynx of elderly patients admitted from inpatient wards or long-term-care facilities often is colonized by gram-negative bacilli4 and could be at risk for becoming colonized with resistant pathogens following antibiotic exposure. Vallés et al2 did not find an increase in resistant pathogens in the late-onset VAP group, but they did not perform surveillance cultures. Given that this was a small, single-center study, it does not provide sufficient evidence to exclude the possibility that the intervention may promote antibiotic resistance. The apparent reduction in early VAP in comatose patients, although an interesting finding, may be a benefit for a patient group for whom the consequences of VAP are less severe.5 Although these benefits are of potential value, they require confirmation in late VAP for which the clinical consequences are more severe. Ultimately, the aim remains to find better ways of preventing VAP that do not rely on the use of antibiotics.