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. 2022 Mar 4;14(3):533.
doi: 10.3390/v14030533.

Estimation of Serial Interval and Reproduction Number to Quantify the Transmissibility of SARS-CoV-2 Omicron Variant in South Korea

Dasom Kim  1 , Sheikh Taslim Ali  2   3 , Sungchan Kim  4 , Jisoo Jo  1   5 , Jun-Sik Lim  6 , Sunmi Lee  4 , Sukhyun Ryu  1
Affiliations

Estimation of Serial Interval and Reproduction Number to Quantify the Transmissibility of SARS-CoV-2 Omicron Variant in South Korea

Dasom Kim et al. Viruses. .

Abstract

The omicron variant (B.1.1.529) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was the predominant variant in South Korea from late January 2022. In this study, we aimed to report the early estimates of the serial interval distribution and reproduction number to quantify the transmissibility of the omicron variant in South Korea between 25 November 2021 and 31 December 2021. We analyzed 427 local omicron cases and reconstructed 73 transmission pairs. We used a maximum likelihood estimation to assess serial interval distribution from transmission pair data and reproduction numbers from 74 local cases in the first local outbreak. We estimated that the mean serial interval was 3.78 (standard deviation, 0.76) days, which was significantly shorter in child infectors (3.0 days) compared to adult infectors (5.0 days) (p < 0.01). We estimated the mean reproduction number was 1.72 (95% CrI, 1.60−1.85) for the omicron variant during the first local outbreak. Strict adherence to public health measures, particularly in children, should be in place to reduce the transmission risk of the highly transmissible omicron variant in the community.

Keywords: SARS-CoV-2; coronavirus; omicron; outbreak; reproduction number; serial interval; transmissibility.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Transmission of the omicron variant of COVID-19 in South Korea in 2021. Transmission chain (A) and epidemic curve (B) of laboratory-confirmed SARS-CoV-2 Omicron variant infection associated with the first local outbreak (n = 76) in South Korea.
Figure 2
Figure 2
Estimated serial interval distributions of the SARS-CoV-2 omicron variant in South Korea. (A) The estimated serial interval distribution was analyzed using the 73 infector–infectee pairs. The vertical red bars indicate the empirical density of the serial intervals calculated from transmission pair data, and the solid black curve indicates fitted normal distribution. Gray vertical lines indicate the presymptomatic transmissions. (B) The estimated serial interval distributions were analyzed by two different age groups of infectors. The fitted serial interval distributions (normal) for child infectors (n = 44 pairs) in solid blue curve and adult infectors (n = 29 pairs) in dashed black curve.
See this image and copyright information in PMC

References

    1. Kim A. Omicron dominant in South Korea. The Korea Herald. 2022. [(accessed on 1 March 2022)]. Available online: http://www.koreaherald.com/view.php?ud=20220124000957.
    1. Mannar D., Saville J.W., Zhu X., Srivastava S.S., Berezuk A.M., Tuttle K.S., Marquez A.C., Sekirov I., Subramaniam S. SARS-CoV-2 Omicron variant: Antibody evasion and cryo-EM structure of spike protein-ACE2 complex. Science. 2022;375:760–764. doi: 10.1126/science.abn7760. - DOI - PMC - PubMed
    1. Brandal L.T., MacDonald E., Veneti L., Ravlo T., Lange H., Naseer U., Feruglio S., Bragstad K., Hungnes O., Odeskaug L.E., et al. Outbreak caused by the SARS-CoV-2 Omicron variant in Norway, November to December 2021. Eurosurveillance. 2021;26:2101147. doi: 10.2807/1560-7917.ES.2021.26.50.2101147. - DOI - PMC - PubMed
    1. Jansen L., Tegomoh B., Lange K., Showalter K., Figliomeni J., Abdalhamid B., Iwen P.C., Fauver J., Buss B., Donahue M. Investigation of a SARS-CoV-2 B.1.1.529 (Omicron) Variant Cluster—Nebraska, November-December 2021. Morb. Mortal. Wkly. Rep. 2021;70:1782–1784. doi: 10.15585/mmwr.mm705152e3. - DOI - PMC - PubMed
    1. Korea Centers for Disease Control and Prevention Agency A Total of 5 Confirmed Cases of Omicron Mutated Virus in Korea Urgent Implementation of Additional Measures to Block Inflow and Prevent Spread. [(accessed on 26 January 2022)]; Available online: https://nih.go.kr/board/board.es?mid=a40303010000&bid=0015&act=view&list....

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