Omicron is posing the greatest challenge yet in China’s ever-changing pandemic situation. With a reproduction number (R0) estimated to be as high as 9.5, one person infected with Omicron can spread the infection to 9.5 persons. Such rapid spread is even faster than chicken pox. And such a fast-spreading virus is difficult to control, forcing the introduction of stricter testing and tracking across China, and even lockdowns in some regions, in order to achieve the goal of “zero-Covid.”
Non-pharmaceutical interventions (NPI) for Covid have been working efficiently, but in the face of a variant with an R0 as high as 9.5, the global situation seems more or less out of control. After it appeared in South Africa, omicron was seen as a severe, difficult to suppress variant. After peaking in South Africa, it subsequently overwhelmed the world. Other countries were not spared in this wave, since their imperfect NPIs could not efficiently and rapidly lower their infection rates.
