A senior World Health Organization (WHO) official on Sept 7 said China is passing a "milestone" since it reported no local COVID-19 infections. However, doctor Bruce Aylward, senior adviser to the WHO director-general and lead of the COVID-19 international experts' mission in China, added that 20 days without local transmission doesn't mean it doesn't have the virus. China's success today, he said, can be attributed to three aspects — namely investment at the State level in the public health infrastructure, the sense of individual responsibility among the Chinese people, and the incredible effort to build additional capacity and preparedness even when infection was heading down.