Professor Gao’s research has focused on the cross-species transmission of pathogenic microorganisms, mechanisms of viral infection, host cellular immunity, and infectious-disease surveillance and control, with particular emphasis on emerging and re-emerging viral diseases. Through sustained leadership of major national research programmes and international collaborative networks, he has contributed to understanding the epidemiology, evolution, transmission, and control of influenza, MERS, Ebola, Zika, chikungunya, COVID-19, and mpox. His research on SARS-CoV-2 included early identification and characterisation of the virus and studies of its structural biology and host interactions. During the COVID-19 pandemic, he also contributed to the development and evaluation of therapeutic and vaccine approaches, including neutralising antibody therapies and recombinant protein subunit vaccines. He has authored more than 900 SCI-indexed publications, with an h-index of 140, and holds more than 90 authorised invention patents. In addition to his research, he has led an Innovative Research Group project supported by the National Natural Science Foundation of China and has participated in the scientific response to multiple infectious-disease emergencies. Collectively, his work reflects a sustained research programme connecting fundamental virology and immunology with infectious-disease surveillance, therapeutic and vaccine development, and international public-health preparedness.