The clinical trial enrolls 130 subjects aged 18 years and older with ≥3 months between their last COVID-19/influenza vaccination or respiratory virus infection. Mucosal and peripheral blood samples will be collected from COVID-19-infected and influenza-infected patients during the preinfection, infection, and recovery periods, and cytokines, immune cell typing, immune cell transcription, and specific antibody levels will be examined in these patients. Levels of cytokines, immune cell typing, immune cell gene transcription, specific antibodies, etc.
