RESUMEN
OBJECTIVE: To investigate the curative efficacy and application value of convalescent plasma (CP) in severe and critical coronavirus disease 2019 (COVID-19) caused by Delta variant. METHODS: The treatment process and results of CP therapy for a patient with critical COVID-19 caused by Delta variant were reported. The clinical application value of CP for COVID-19 caused by Delta variant was analyzed along with the literature review. RESULTS: Our case was a 50-year-old male, who was imported from abroad and had not been vaccinated against COVID-19. The novel coronavirus nucleic acid test was negative before entry. On the second day after entry, fever occurred, novel coronavirus nucleic acid test was positive. Chest CT images showed bilateral multiple mottling and ground-glass opacity with symptoms of nausea, headache, loss of appetite, diarrhea, but no running nose, nasal obstruction, dyspnea, abnormal smell and taste. The infection rapidly developed from medium to critical. On the basis of standard treatment, Delta variant CP was intravenous dripped on the 10th day of hospital admission (the 6th day after becoming severe). The patient's condition improved rapidly. CONCLUSIONS: The curative efficacy evaluation of this patient proved that CP therapy is of great value in the treatment of severe and critical COVID-19.