Dr. Chan’s main research interests are the virus-host interaction and pathogenesis of influenza virus and coronavirus (SARS-CoV-2, SARS-CoV and MERS-CoV) using ex vivo human respiratory explant cultures and in vitro well-differentiated human respiratory epithelial cells. Major focuses of his current work are: (1) Risk assessment of influenza virus and coronavirus using ex vivo explants and in vitro respiratory epithelial cells model. (2) Mechanism of lung injury upon severe influenza virus and coronavirus infection (3) Human nasal, nasopharyngeal, airway and distal lung organoids development and risk assessment for emerging infectious diseases (4) Role of human distal airway stem cells in respiratory epithelium regeneration upon influenza H5N1 virus, SARS-CoV-2, MERS-CoV and SARS-CoV infection. (5) Role of mesenchymal stromal cells and exosomes/microvesicles in reverse influenza H5N1 associated acute lung injury (6) Novel therapeutic options for severe human influenza virus and coronavirus infection, e.g. COVID-19.