2.2. Exclusion criteria
AIDS, immune deficiency
AIDS, IMMUNE DEFICIENCY, MALIGNANT TUMORS, CAVITY, CHRONIC SINUSITIS
Refusal to participate.Any severe cases of COVID-19.Patients with a history of nasal surgery, chronic sinusitis or drug intervention through nasal cavity.Women in the period of pregnancy or lactation.Patients with immune deficiency (such as patients with malignant tumors, organ or bone marrow transplants, AIDS, and those taking immunosuppressive drugs within 3 months).Other patients that were considered unsuitable to participate in this study.