The new variant poses a particular threat to China's hitherto successful zero-Covid strategy at a time when the country's economy is looking vulnerable.

Ed Butler gets the latest on the fast-moving Omicron variant from Boston University epidemiologist Eleanor Murray. One new development is a recent study in Hong Kong that found that one of the two main Chinese vaccines offers very little resistance against it. Health security expert Nicholas Thomas of Hong Kong's City University says the Chinese government is now in a race to deliver booster vaccines to its population, while stopping Omicron from leaching across its porous land borders.

It comes at a sensitive time, with the Beijing Winter Olympics to begin in February, and the government seeking to gently deflate a property market bubble ahead of a politically sensitive Communist Party Congress in October. But independent economist Andy Xie says that when push comes to shove, the government would rather lockdown the entire national economy rather than let Covid get out of control.

Producer: Laurence Knight

(Picture: A large crowd of commuters wearing face masks at a subway station in Hong Kong; Credit: Budrul Chukrut/SOPA Images/LightRocket via Getty Images)