Hezhao Ji

1. Introduction Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a sister clade of SARS-CoV (Coronaviridae Study Group of the International Committee on Taxonomy of Viruses et al., 2020), has posed a global public health threat since its initial outbreak in December 2019 (Hu et al., 2020). On May 5, 2023, the World Health Organization (WHO) declared the end of the 2019 novel coronavirus disease (COVID-19) pandemic as a Public Health Emergency of International Concern.

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