Zhang Fang, a member of the emergency management department at the SCDC who worked in Sun's special task force, says Sun is like a "chess master who thinks 10 steps ahead".

"Our work is like a deep river which seems peaceful on the surface, but with lots of undertows and risks," says Sun. "That's why it is of vital importance to always plan ahead."

Sun attributes Shanghai's success in containing the epidemic to early planning and decisive action. The next big step, he says, would be the development of an effective vaccine for the virus.

He believes that Chinese scientists would be able to develop the vaccine sooner than their peers in other countries.

An expert in vaccination, Sun has been the chief organizer for the planning of public vaccination activities in Shanghai. He was the person who proposed and implemented the practice of providing people age 60 and older in Shanghai with free vaccine shots for respiratory diseases. He also spearheaded the compilation of China's first provincial-level vaccination working protocol, which is frequently updated.

"Now, Sun wants to make sure that all those who failed to get their vaccination shots during the COVID-19 outbreak can do so," says Wu Linlin from the SCDC's vaccination-planning department. "He is now working with us to craft a strategy aimed at vaccinating the priority population."