On 2021-03-02 a superspreading event most likely occurred in Washington. 26 days later (2021-03-29) it started to super-spread through the community. A total of 36 copies of this genome (that represents the core of the outbreak), were reported in Gisaid, a proxy for primary transmissions, along with 274 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, 31 days after it started, with 6990 sequences found in total.
The last sequence of the superspreading event was collected on 2021-05-04.
The sequence of this event has been classified as Alpha.