-Availability of data and materials
All data are publicly available. https://ourworldindata.org/grapher/covid-variants-area Competing interests
The authors declare that they have no competing interests.-Funding The work described in this paper was partially supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (HKU C7123-20G).
-Authors’ contributionsAll authors conceived the study, carried out the analysis, wrote the draft, revised the manuscript critically, and approved it for publishing.
Funding The work described in this paper was partially supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (HKU C7123-20G).
-AcknowledgementsNone.