Abstract

The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first detected in October 2021, possessed many mutations compared to previous variants. We aimed to identify and analyze SARS-CoV-2 Omicron subvariants among coronavirus disease 2019 (COVID-19) patients between January 2022 and September 2022 in Taiwan. The results revealed that BA.2.3.7, featuring K97E and G1251V in the spike protein compared with BA.2, emerged in March 2022 and persistently dominated between April 2022 and August 2022, resulting in the largest COVID-19 outbreak since 2020. The accumulation of amino acid (AA) variations, mainly AA substitution, in the spike protein was accompanied by increasing severity in Omicron-related COVID-19 between April 2022 and January 2023. Older patients were more likely to have severe COVID-19, and comorbidity was a risk factor for COVID-19-related mortality. The accumulated case fatality rate (CFR) dropped drastically after Omicron variants, mainly BA.2.3.7, entered Taiwan after April 2022, and the CFR was 0.16% in Taiwan, which was lower than that worldwide (0.31%) between April 2021 and January 2023. The relatively low CFR in Omicron-related COVID-19 patients can be attributed to adjustments to public health policies, promotion of vaccination programs, effective antiviral drugs, and the lower severity of the Omicron variant.

Details

Title
Epidemiology and analysis of SARS-CoV-2 Omicron subvariants BA.1 and 2 in Taiwan
Author
Liu, Li-Teh 1 ; Chiou, Shyh-Shin 2 ; Chen, Po-Chih 3 ; Chen, Chun-Hong 4 ; Lin, Ping-Chang 5 ; Tsai, Ching-Yi 5 ; Chuang, Wan-Long 6 ; Hwang, Shang-Jyh 7 ; Chong, Inn-Wen 8 ; Tsai, Jih-Jin 9   VIAFID ORCID Logo 

1  Chung Hwa University of Medical Technology, Department of Medical Laboratory Science and Biotechnology, College of Medical Technology, Tainan City, Taiwan (GRID:grid.411636.7) (ISNI:0000 0004 0634 2167) 
2  Kaohsiung Medical University, Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung City, Taiwan (GRID:grid.412019.f) (ISNI:0000 0000 9476 5696); Kaohsiung Medical University, Center of Applied Genomics, Kaohsiung City, Taiwan (GRID:grid.412019.f) (ISNI:0000 0000 9476 5696); Kaohsiung Medical University Hospital, Division of Pediatric Hematology and Oncology, Department of Pediatrics, Kaohsiung City, Taiwan (GRID:grid.412027.2) (ISNI:0000 0004 0620 9374) 
3  Kaohsiung Medical University Hospital, Department of Laboratory Medicine, Kaohsiung City, Taiwan (GRID:grid.412027.2) (ISNI:0000 0004 0620 9374); Kaohsiung Medical University, Department of Medical Laboratory Science and Biotechnology, Kaohsiung City, Taiwan (GRID:grid.412019.f) (ISNI:0000 0000 9476 5696) 
4  National Mosquito-Borne Diseases Control Research Center, National Health Research Institutes, Zhunan, Taiwan (GRID:grid.59784.37) (ISNI:0000 0004 0622 9172); National Health Research Institutes, National Institute of Infectious Diseases and Vaccinology, Zhunan, Taiwan (GRID:grid.59784.37) (ISNI:0000 0004 0622 9172) 
5  Kaohsiung Medical University Hospital, Tropical Medicine Center, Kaohsiung City, Taiwan (GRID:grid.412027.2) (ISNI:0000 0004 0620 9374) 
6  Kaohsiung Medical University, School of Medicine, College of Medicine, Kaohsiung City, Taiwan (GRID:grid.412019.f) (ISNI:0000 0000 9476 5696); Kaohsiung Medical University Hospital, Hepatobiliary Division, Department of Internal Medicine, Kaohsiung City, Taiwan (GRID:grid.412027.2) (ISNI:0000 0004 0620 9374) 
7  Kaohsiung Medical University, School of Medicine, College of Medicine, Kaohsiung City, Taiwan (GRID:grid.412019.f) (ISNI:0000 0000 9476 5696); Kaohsiung Medical University Hospital, Division of Nephrology, Department of Internal Medicine, Kaohsiung City, Taiwan (GRID:grid.412027.2) (ISNI:0000 0004 0620 9374) 
8  Kaohsiung Medical University, Department of Internal Medicine and Graduate Institute of Medicine, Kaohsiung City, Taiwan (GRID:grid.412019.f) (ISNI:0000 0000 9476 5696); Kaohsiung Medical University Hospital, Department of Pulmonary Medicine, Kaohsiung City, Taiwan (GRID:grid.412027.2) (ISNI:0000 0004 0620 9374) 
9  Kaohsiung Medical University Hospital, Tropical Medicine Center, Kaohsiung City, Taiwan (GRID:grid.412027.2) (ISNI:0000 0004 0620 9374); Kaohsiung Medical University, School of Medicine, College of Medicine, Kaohsiung City, Taiwan (GRID:grid.412019.f) (ISNI:0000 0000 9476 5696); Kaohsiung Medical University Hospital, Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung City, Taiwan (GRID:grid.412027.2) (ISNI:0000 0004 0620 9374) 
Pages
16583
Publication year
2023
Publication date
2023
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41598-023-43357-7
ProQuest document ID
2871984548
Copyright
© The Author(s) 2023. corrected publication 2024. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.