On 2021-03-16 a superspreading event most likely occurred in Japan. 11 days later (2021-03-27) it started to super-spread through the community. A total of 61 copies of this genome (that represents the core of the outbreak), were reported in Gisaid, a proxy for primary transmissions, along with 185 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, 17 days after it started, with 3729 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.