Photo taken on March 30, 2021 shows the entrance of the headquarters of the World Health Organization (WHO) in Geneva, Switzerland. (Xinhua/Chen Junxia)

Echoing Heymann, Peter C. Doherty, a Nobel Prize winner, has recently told Xinhua that "It may be that we will never know exactly where this virus came from. And I don't think that will make any real difference to how these viruses are handled."

"We always want to blame someone. And I don't think that's what it's about," he added. "It's not blaming people, it's dealing with the problem."

(Video reporter: Du Yang; Video editors: Liu Hongde, Wang Jingyun, Liu Fangqiang, Zu Shiqi, Zhang Qiru)