COVID-19 outbreaks caused by different SARS-CoV-2 variants: a descriptive, comparative study from China

Cao Chen; Yenan Feng; Zeyuan Yin; Mingfan Pang; Qi Shi; Xuejun Ma; Xiao-Ping Dong

doi:10.3389/fpubh.2024.1416900

COVID-19 outbreaks caused by different SARS-CoV-2 variants: a descriptive, comparative study from China

Front Public Health. 2024 Dec 12:12:1416900. doi: 10.3389/fpubh.2024.1416900. eCollection 2024.

Authors

Cao Chen^{1

2}, Yenan Feng¹, Zeyuan Yin¹, Mingfan Pang³, Qi Shi^{1

4}, Xuejun Ma^{1

2}, Xiao-Ping Dong^{1

2

4

5}

Affiliations

¹ National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, NHC Key Laboratory of Medical Virology and Viral Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
² Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China.
³ Center for Global Public Health, Chinese Center for Disease Control and Prevention, Beijing, China.
⁴ China Academy of Chinese Medical Sciences, Beijing, China.
⁵ Shanghai Institute of Infectious Disease and Biosafety, Shanghai, China.

Abstract

Objectives: To understand the epidemic characteristics of various SARS-CoV-2 variants, we mainly focus on analyzing general epidemic profiles, viral mutation, and evolution of COVID-19 outbreaks caused by different SARS-CoV-2 variants of concern (VOCs) in China as of August 2022.

Methods: We systematically sorted out the general epidemic profiles of outbreaks caused by various SARS-CoV-2 VOCs in China, compared the differences of outbreaks caused by Delta and Omicron VOCs, and analyzed the mutational changes of subvariants between the same outbreak and different outbreaks.

Findings: By 15 August 2022, a total of 2, 33, and 124 COVID-19 outbreaks caused by Alpha, Delta, and Omicron VOCs, respectively, were reported in different regions of China. In terms of the number of outbreaks, the extent of affected areas, and the total number of confirmed cases, Omicron VOCs were more widespread than the other variants. The most frequently circulating PANGO lineages in China were B.1.617.2 and AY.122 in Delta VOCs, and BA.2.2.1, BA.2, BA.2.2, and BA.5 for Omicron VOCs. Additional mutations in the genome of the SARS-CoV-2 strain were frequently observed in outbreaks with longer duration and higher numbers of infections.

Conclusion: Through the comprehensive analysis of the COVID-19 outbreaks, the influences, and the evolution of the SARS-CoV-2 variants in China, we found differences between outbreaks caused by Delta and Omicron VOCs. The genome of SARS-CoV-2 continued to evolve within the same outbreak and across outbreaks occurring in different locations or at different times. These findings suggest that rapidly containing an Omicron virus outbreak can not only reduce the spread of the virus but also delay the virus's mutation frequency.

Keywords: COVID-19; SARS-CoV-2; omicron; outbreak; variants.

Publication types

Comparative Study

MeSH terms

COVID-19* / epidemiology
China / epidemiology
Disease Outbreaks* / statistics & numerical data
Humans
Mutation*
SARS-CoV-2* / genetics

Supplementary concepts

SARS-CoV-2 variants

Grants and funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. This study was supported by the National Natural Science Foundation of China (82341035 and 82341034), SKLID Development Grant (2021SKLID504, 2019SKLID401, 2019SKLID603).