The novel coronavirus is a previously undetected virus that is highly infectious. The new coronavirus has a higher affinity for human airway epithelial receptors than the SARS coronavirus, so it is considered much more infectious than the SARS coronavirus. Patients with new coronavirus pneumonia develop severe respiratory failure, which is more rapidly progressive than SARS but less lethal than SARS, and new coronavirus causes slightly less structural damage and necrosis to the lungs of patients than SARS, and no severe fibrosis.