Prof. Zhijie An is a researcher at the Immunization Program Center of the Chinese Center for Disease Control and Prevention, a Master’s student tutor, and a tutor of the China Field Epidemiology Training Project (CFETP). He worked at the WHO Representative Office in China and was a visiting scholar at Emory University and CDC in the United States from 2016 to 2017. He concurrently serves as an expert on the Hepatitis A Vaccine Working Group of the WHO Advisory Committee of Experts on Immunization Strategy (SAGE), and is a member of the Field Epidemiology Group of the Public Health Branch of the Chinese Medical Association, a member of the Vaccine and Immunization Branch and the Biological Products Branch of the Chinese Society of Preventive Medicine, and a clinical research member of the Chinese Vaccine Industry Association. In 2020, he was selected for the National Health Science Popularization Expert Database. He has long been engaged in work related to vaccines and planning immunization, and has carried out work in the fields of the surveillance and prevention of vaccine-preventable diseases, research on immunization strategies, the formulation of guidelines for vaccine use, vaccine post-marketing research, emergency responses to vaccine-related emergencies, and foreign assistance for global public health .