CRP and viral pneumonia: The current study demonstrated that a) PCT, CRP and WBC values are significantly higher in CAP due to classical bacterial pathogens compared to atypical bacterial or viral pneumonia, b) PCT levels increase with an increasing CRB-65 score as a marker of the severity of CAP and c) PCT levels and CRB-65 score show a comparable power to detect CAP patients that will be hospitalised, whereas CRP or WBC have very poor discriminatory power in this point.