Besides its terrible claim in terms of human lives, SARS-CoV-2 pandemic hit hard also on the hospital management with most healthcare facilities being overwhelmed by hundreds of patients with SARS-CoV-2-related symptoms. Therefore, hospitals needed to combine prevention of in-hospital SARS-CoV-2 spread and maintenance of standard of care for non-SARS-CoV-2 patients. Such challenges also affected Italian facilities that were then reorganized with entire buildings dedicated to SARS-CoV-2. 1,2 Similarly, also the IRCCS San Martino Hospital in Genoa (Italy) created separate pathways for SARS-CoV-2-free and SARS-CoV-2-positive patients, both in the emergency department and in the different wards with our Internal Medicine division being designated as SARS-CoV-2-free by the director of the hospital. A major pitfall of such strategy was immediately identified in the rather long time of COVID-19 incubation, which may hamper the allocation of patients to the correct and safe pathways. This issue was previously investigated by our research group in a recently published article in the European Journal of Clinical Investigation (EJCI), reporting clinical and laboratory variables useful to predict late in-hospital SARS-CoV-2 positivity. 3 Such patientsadmitted at the ED as negative at the first test-were then found positive for the virus during short-term follow-up testing, when they already passed the filter 'grey' zones. During the second and third waves of virus spread, the IRCCS San Martino Hospital-the biggest healthcare facility of the Liguria Region-demonstrated great plasticity and adaptation by creating every week new COVIDdedicated units and moving the filter zones within the COVID-free wards. However, the big issue of incubation time remained and, given the high number of multiple occupancy rooms in our hospital, COVID-free units had