Review of the early reports of the epidemiological characteristics of the B.1.1.7 variant of SARS-CoV-2 and its spread worldwide

The variant B.1.1.7 of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the RNA virus causing the pandemic more than a year worldwide, was reported from United Kingdom (UK) in late December 2020. It was reported that mortality increases by 65% and transmissibility increases by 70%, which may result in an increase of reproduction number to 1.13-1.55 from 0.75-0.85. To analyze the global increasing trend of the variant B.1.1.7, we extracted results of B.1.1.7 from GISAID on May 11 and May 12, 2021, and conducted a dose-response regression. It took 47 days to reach 20% and 121 days to reach 50% among the sequence submitted from UK. In Korea, cases of B.1.1.7 have increased since the first report of three cases on December 28, 2020. Positive rate of B.1.1.7 in Korea was 21.6% in the week from May 9 to May 15, 2021. Detection rate of the variants is expected to increase further and new variants of SARS-CoV-2 are emerging, so a close monitoring and control would be maintained for months.