Introduction of ORF3a-Q57H SARS-CoV-2 Variant Causing Fourth Epidemic Wave of COVID-19, Hong Kong, China
Daniel K. W. Chu, Kenrie P. Y. Hui, Haogao Gu, Ronald LW Ko, Pavithra Krishnan, Daisy Y.M. Ng, Gigi Y.Z. Liu, Carrie K.C. Wan, Man-chun Cheung, Ka‐Chun Ng, John M. Nicholls, Dominic N.C. Tsang, Malik Peiris, Michael C. W. Chan, Leo L. M. Poon
Abstract
H ong Kong, China, has had 4 waves of corona- virus disease (COVID-19) outbreaks since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019. By February 1, 2021, Hong Kong had recorded 10,453 reverse transcription PCR (RT-PCR)-confi rmed CO-VID-19 cases, and many of those occurred during the last 2 waves. The third wave occurred during late June to early September 2020 and was caused by a single introduction of GISAID (https://platform.gisaid.org) clade GR virus (1). The fourth wave began in early November 2020 and was caused by a newly introduced GISAID clade GH SARS-CoV-2 (1). We describe the origin of a clade GH virus causing the fourth epidemic wave in Hong Kong.