Superspreading in the emergency of COVID-19 variants

Gómez-Carballa, Alberto; Pardo-Seco, Jacobo; Bello, Xabier; Martinón-Torres, Federico; Salas, Antonio

Superspreading and Variants of Concern (VOC) of the human pathogen, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are the main catalyzers of the coronavirus disease 2019 (COVID-19) pandemic. Measuring their individual impact is however challenging. By examining the largest database of SARS-CoV-2 genomes The Global Initiative on Sharing Avian Influenza Data (GISAID; n > 1.2M high quality sequences), we present evidence suggesting that superspreading has played a key role in the epidemiological predominance of VOC. There are clear signatures in the database compatible with large superspreading events coinciding chronologically with the worst epidemiological scenarios triggered by VOC. The data suggest that, without the randomness effect of the genetic drift facilitated by superspreading, new VOC of SARS-CoV-2 would have had more limited chance of success.