ABSTRACT
RATIONALE: Paxlovid has shown the potential decreasing the hospitalization rate of mild or moderate coronavirus disease 2019 (COVID-19) and death in few of clinical trials, and is expected to the most promising medicine targeting Severe Acute Respiratory Syndrome Coronavirus 2 (SRAS-COV-2). However, there are no enough evidences to show it effectiveness for all patients with SARS-COV-2, especially among elderly patients and newest Omicron variant. PATIENT CONCERNS AND DIAGNOSIS: A 79 year's old female patient was admitted to hospital because of the moderate COVID-19 caused by the Omicron variant BA2.0. He presented the initial syndromes including Xerostomia, cough and fever. Chest computed tomography (CT) scanning at admission showed the exudation lesions on lung. The laboratory examination revealed that there are increased C-reactive protein (CRP), Ferritin and erythrocytesedimentationrate (ESR) and decreased white blood cells. INTERVENTIONS: The oral Paxlovid (Nirmatrelvir/Ritonavir) was administrated on second day after admission. OUTCOMES: The syndromes of Xerostomia, cough and fever was improved on third day after use of Paxlovid. The levels of CRP, ESR and counts of white blood cells returned the normal after three days of admission. The chest CT scanned on the third and sixth day after Paxlovid used showed the absorption of lesions. The examination of SARS-COVS viral nucleic acid turned negative at fifth day of admission. LESSONS: As a result, we would consider that Paxlovid is a suitable oral drug for elderly patients with SARS-COV2 even Omicron variant, it's benefit to improve patient's symptom and signs and can prevents COVID-19 with the high-risk factors from severe disease, although it didn't shorten the time for viral nucleic acid to turn negative.