[4] This enabled him to change his career direction to infectious disease research, and he joined the faculty of the university as a teaching assistant and later lecturer in virology.

[4] In 1999, Gao moved to Harvard Medical School as a Wellcome Trust International Travelling Fellow and conducted research under Don Craig Wiley and Stephen C. Harrison until 2001.

[3] In 2008 he was appointed Vice President of Beijing Institutes of Life Science and Director of the National Key Laboratory of Pathogenic Microorganism and Immunology of the CAS.

[9] Gao's main research focus is on the mechanism of viral entry and release, especially the cross-species transmission (host jump) of the influenza virus.

During the peak of the 2014 Ebola outbreak, he spent two months leading the China Mobile Test Laboratory in Sierra Leone from September to November, playing a role that is described by the US National Academy of Sciences as "heroic" in fighting the epidemic.