Reproduction number of SARS-CoV-2 Omicron variants, China, December 2022-January 2023

China adjusted the zero-COVID strategy in late 2022, triggering an unprecedented Omicron wave. We estimated the time-varying reproduction numbers of 32 provincial-level administrative divisions from December 2022 to January 2023. We found that the pooled estimate of initial reproduction numbers is 4.74 (95% confidence interval: 4.41, 5.07).

Automated summary

China adjusted its zero-COVID strategy in late 2022, leading to an unprecedented Omicron wave. We conducted a study estimating the time-varying reproduction numbers of 32 provincial-level administrative divisions from December 2022 to January 2023. The pooled estimate revealed an initial reproduction number of 4.74 (95% confidence interval: 4.41, 5.07).