Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Nov 23;20(1):451.
doi: 10.1186/s12916-022-02655-z.

Identifying susceptibility of children and adolescents to the Omicron variant (B.1.1.529)

June Young Chun #  1 , Hwichang Jeong #  2 , Yongdai Kim  3
Affiliations

Identifying susceptibility of children and adolescents to the Omicron variant (B.1.1.529)

June Young Chun et al. BMC Med. .

Abstract

Background: The Omicron variant (B.1.1.529) is estimated to be more transmissible than previous strains of SARS-CoV-2 especially among children, potentially resulting in croup which is a characteristic disease in children. Current coronavirus disease 2019 (COVID-19) cases among children might be higher because (i) school-aged children have higher contact rates and (ii) the COVID-19 vaccination strategy prioritizes the elderly in most countries. However, there have been no reports confirming the age-varying susceptibility to the Omicron variant to date.

Methods: We developed an age-structured compartmental model, combining age-specific contact matrix in South Korea and observed distribution of periods between each stage of infection in the national epidemiological investigation. A Bayesian inference method was used to estimate the age-specific force of infection and, accordingly, age-specific susceptibility, given epidemic data during the third (pre-Delta), fourth (Delta driven), and fifth (Omicron driven) waves in South Korea. As vaccine uptake increased, individuals who were vaccinated were excluded from the susceptible population in accordance with vaccine effectiveness against the Delta and Omicron variants, respectively.

Results: A significant difference between the age-specific susceptibility to the Omicron and that to the pre-Omicron variants was found in the younger age group. The rise in susceptibility to the Omicron/pre-Delta variant was highest in the 10-15 years age group (5.28 times [95% CI, 4.94-5.60]), and the rise in susceptibility to the Omicron/Delta variant was highest in the 15-19 years age group (3.21 times [95% CI, 3.12-3.31]), whereas in those aged 50 years or more, the susceptibility to the Omicron/pre-Omicron remained stable at approximately twofold.

Conclusions: Even after adjusting for contact pattern, vaccination status, and waning of vaccine effectiveness, the Omicron variant of SARS-CoV-2 tends to propagate more easily among children than the pre-Omicron strains.

Keywords: Adolescent; B.1.1.529 SARS-CoV-2 variant; Bayesian analysis; COVID-19; Child; Mathematical model; SARS-CoV-2; Susceptibility.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Characteristics of the SARS-CoV-2 outbreak in South Korea: A epidemic curve and national interventions, B national seroprevalence data*, and C domestic composition of variant strains during the study period. *The seroprevalence of SARS-CoV-2-specific anti-nucleocapsid (anti-N) and anti-spike (anti-S) antibodies have been studied in samples from the Korea National Health and Nutrition Examination Survey which included participants aged 10 years or more. The seroprevalence study was performed in samples from blood donors (aged 20 to 59 years) in December 2021, only. The number denotes the sample size of each study
Fig. 2
Fig. 2
Age distribution of COVID-19 cases (A) during the 3rd, 4th, and 5th waves in South Korea and B those normalized by the demographic structure. The age-varying susceptibility to SARS-CoV-2 (C) during the 3rd (pre-Delta), 4th (Delta), and 5th (Omicron) waves in South Korea and D the fold rise in susceptibility to the Omicron/Delta and Omicron/pre-Delta by age groups. The shadow indicates the 95% confidence intervals
See this image and copyright information in PMC

References

    1. Belay ED, Godfred-Cato S. SARS-CoV-2 spread and hospitalisations in paediatric patients during the omicron surge. Lancet Child Adolescent Health. 2022;6(5):280–281. doi: 10.1016/S2352-4642(22)00060-8. - DOI - PMC - PubMed
    1. Clarke KEN, Jones JM, Deng Y, Nycz E, Lee A, Iachan R, et al. Seroprevalence of infection-induced SARS-CoV-2 antibodies - United States, September 2021-February 2022. MMWR Morb Mortal Wkly Rep. 2022;71(17):606–608. doi: 10.15585/mmwr.mm7117e3. - DOI - PMC - PubMed
    1. UK Health Security Agency. SARS-CoV-2 variants of concern and variants under investigation in England. Technical briefing 34: UK Health Security Agency; 2022. [Available from: https://assets.publishing.service.gov.uk/government/uploads/system/uploa...]. Accessed 31 May 2022.
    1. World Health Organization. Coronavirus disease (COVID-19): vaccines: World Health Organization; 2022 [Available from: https://www.who.int/news-room/questions-and-answers/item/coronavirus-dis...]. Accessed 31 May 2022.
    1. Davies NG, Klepac P, Liu Y, Prem K, Jit M, Eggo RM. Age-dependent effects in the transmission and control of COVID-19 epidemics. Nat Med. 2020;26(8):1205–1211. doi: 10.1038/s41591-020-0962-9. - DOI - PubMed

Publication types

Substances

Supplementary concepts