How concerned should we be about asymptomatic carriers?

Join us to find out how concerned we should be about asymptomatic carriers. Respiratory expert Zhong Nanshan gives his opinion on the issue in China and abroad. Experts have warned that asymptomatic carriers of the novel coronavirus may pose a great transmission risk as imported cases become the major challenge China faces and the number of confirmed COVID-19 patients surpasses 700,000 globally.