2025 Articles

Retrospective analysis of estimated serial interval and reproductive number of SARS-CoV-2 Omicron variant in Korea

Zhu, Chunjuan; Cheng, Cheng; Guo, Jia; Feng, Xiaomei; Sun, Qiwen

The novel Severe Acute Respiratory Syndrome Coronavirus type 2 (SARS-CoV-2) threatens the global economy and public health, and therefore it is significant to research the intervention measures of this virus. In this study, we estimated the serial interval and reproductive number of the SARS-CoV-2 Omicron B1.1.529 variation, which can serve as indicators of the transmission potential of the Omicron variant in Korea from November 25 to December 30, 2021.

By examining 427 local omicron cases and constructing 65 transmission pairs, we estimated a mean continuous interval of 2.23 days and a mean number of regenerations of 1.30 for one of the kindergarten transmission chains using maximum likelihood estimation. Our research indicates that Omicron has a shorter serial interval, faster transmission, and greater immune evasion capacity than earlier variants. To effectively control community transmission of Omicron, it is necessary to rapidly track recent contacts, isolate asymptomatic individuals, adhere rigorously to public health policies, and enhance immunization efforts among teenagers. The retrospective analysis of the indexes may give us new guidance for the new infectious diseases in the future.