Inclusion criteria:  Aged >65 years Suspected community-acquired or nursing-home acquired pneumonia consulting to the emergency room with at least one respiratory symptom (new or increasing among: cough, purulent sputum, pleuritic chest pain, dyspnea, respiratory rate >20/min, focal auscultatory findings or oxygen saturation <90% on room air) AND at least one symptom or laboratory finding compatible with an infection (temperature >37.8°C or <36.0°C, C reactive protein (CRP) >10 mg/L, PCT >0.25 µg/L, leukocyte count >10 G/L with >85% neutrophils or band forms) Signed informed consent In the oldest old (patients aged >80 years), the presence of acute delirium or unexplained acute fall can substitute for the presence of either the respiratory or the infectious symptom  Exclusion Criteria:  Immediate admission to the intensive care unit (ICU) Pneumonia in the past 3 months PCR or antigenic test positive for SARS-CoV-2 in the 3 past weeks Transfer from another hospital with a diagnosis of pneumonia CXR or thoracic CT scan or US already done during the present episode Immediate contrast-enhanced CT scan needed Advanced care planning limiting therapy to comfort care only Prisoners Known uncontrolled psychiatric disorders Previous enrollment into the current study.