On 2021-03-13 a superspreading event most likely occurred in Japan. 9 days later (2021-03-22) it started to super-spread through the community. A total of 108 copies of this genome (that represents the core of the outbreak), were reported in Gisaid, a proxy for primary transmissions, along with 100 genomes that are one-step mutation with respect to the core genome (a proxy for secondary transmissions). The signature for the likely superspreading event ends at about 2021-04-03, 20 days after it started, with 4045 sequences found in total.
The last sequence of the superspreading event was collected on 2021-04-03.
The sequence of this event has been classified as Alpha.