Severity of SARS-CoV-2 Omicron XBB subvariants in Singapore

Rachael Pung; Xin Peng Kong; Lin Cui; Sae-Rom Chae; Mark I-Cheng Chen; Vernon J Lee; Zheng Jie Marc Ho

doi:10.1016/j.lanwpc.2023.100849

Severity of SARS-CoV-2 Omicron XBB subvariants in Singapore

Lancet Reg Health West Pac. 2023 Jul 25:37:100849. doi: 10.1016/j.lanwpc.2023.100849. eCollection 2023 Aug.

Authors

Rachael Pung^{1

2}, Xin Peng Kong¹, Lin Cui³, Sae-Rom Chae^{1

3}, Mark I-Cheng Chen^{1

3}, Vernon J Lee^{1

3

4}, Zheng Jie Marc Ho^{1

4}

Affiliations

¹ Ministry of Health, Singapore.
² Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, United Kingdom.
³ National Centre for Infectious Diseases, Singapore.
⁴ Saw Swee Hock School of Public Health, National University of Singapore, Singapore.

Abstract

Several XBB subvariants such as XBB.1.5, XBB.1.9, XBB.1.16 and XBB.2.3 co-circulate in Singapore. Despite the different viral properties of XBB.1.16 as compared to other XBB subvariants, comparison on their severity is limited. In this study, we investigate the outcomes of hospitalisation and severe COVID-19 infection in individuals infected with different XBB subvariants, adjusted for potential confounders such as age and vaccination history. Overall, our preliminary analysis showed that the risk of severe outcomes when infected with XBB.1.16 is higher than that of XBB.1.5 or XBB.1.9 but there is no difference in the risk of hospitalisation across different XBB subvariants.