He is a fellow of the Royal College of Pathologists specializing in clinical virology. Dr. Chan is now working as Scientific Officer and is also an Honorary Associate Professor in the Department of Microbiology, University of Hong Kong. His research primary focuses on EBV-associated diseases and rapid diagnosis of respiratory virus infection. Dr. Chan is the first person worldwide successfully isolated SARS-CoV-1 deadly virus from infected patients using monkey fetal kidney cells in 2003. Currently, he works on immunology and antiviral agents against emerging infectious diseases including SARS CoV-2, Monkeypox and Influenza. He has made significant contributions in these areas as evidenced by his publications in New England Journal of Medicine, Cells, Lancet, Lancet Infectious Diseases, Nature Medicine, Nature Genetics and Nature Communications etc. He is ranked as international top 1% of highly cited researchers by Clavariate Analytics in 2015, 2016, 2021, 2022 and 2023. Outstanding Team Award by the Hospital Authority was obtained in 1999 (H5N1), 2003 (SARS-CoV-1) and Swine H1N1 (2010).