International Institute for Zoonosis Control, Hokkaido University, Hokkaido, Japan.
Graduate School of Infectious Diseases, Hokkaido University, Hokkaido, Japan.
Euro Surveill. 2021 Jul;26(27). doi: 10.2807/1560-7917.ES.2021.26.27.2100570.
Using numbers of SARS-CoV-2 variants detected in Japan as at 13 June 2021, relative instantaneous reproduction numbers (R) of the R.1, Alpha, and Delta variants with respect to other strains circulating in Japan were estimated at 1.25, 1.44, and 1.95. Depending on the assumed serial interval distributions, R varies from 1.20-1.32 for R.1, 1.34-1.58 for Alpha, and 1.70-2.30 for Delta. The frequency of Delta is expected to take over Alpha in Japan before 23 July 2021.
使用截至 2021 年 6 月 13 日在日本检测到的 SARS-CoV-2 变体数量，估算了 R.1、Alpha 和 Delta 变体相对于日本其他流行株的相对瞬时繁殖数（R），分别为 1.25、1.44 和 1.95。根据假设的连续间隔分布，R.1 的 R 值在 1.20-1.32 之间，Alpha 的 R 值在 1.34-1.58 之间，Delta 的 R 值在 1.70-2.30 之间。预计 2021 年 7 月 23 日之前，日本 Delta 的流行频率将超过 Alpha。
