Superspreading in the emergence of COVID-19 variants. Issue 12 (December 2021)

• Record Type: Journal Article
• Authors: Gómez-Carballa, Alberto; Pardo-Seco, Jacobo; Bello, Xabier; Martinón-Torres, Federico; Salas, Antonio
• Is Part Of: Trends in genetics. Volume 37:Issue 12(2021)
• Page Start: 1069
• Page End: 1080
• Publication Date: 2021-12
• Subjects: SARS-CoV-2 -- superspreader -- superspreader event -- variant of concern -- B.1.1.7 -- B.1.617.2; Genetics -- Periodicals; 576.5
• DOI: 10.1016/j.tig.2021.09.003
• Languages: English
• ISSNs: 0168-9525

Abstract

Abstract : 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. However, measuring their individual impact is challenging. By examining the largest database of SARS-CoV-2 genomes The Global Initiative on Sharing Avian Influenza Data [GISAID; n >1.2 million high-quality (HQ) sequences], we present evidence suggesting that superspreading has had a key role in the epidemiological predominance of VOC. There are clear signatures in the database compatible with large superspreading events (SSEs) 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. Highlights: Viral genome phylogenies reflect patterns of virus transmissions (e.g., signatures left by transmission chains differ from those left by superspreading). Due to an incubation time of ~5 to 6 days and an evolutionary rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the order of ~10 –3, superspreading transmissions generate starlike phylogenies that find perfect parallelism in contact tracing networks. It is likely that thousands of variants of concern (VOC) passed unnoticed to genome databases because they have died out before having the opportunity to emerge in the population (or have not been sampled). Given that mutational changes occur in a nearly constant way, it is not obvious how to determine the mutation/s that make the virus more infectious. The algorithm of the pandemic is not simple and superspreading should be considered as one of the main catalyzers of the SARS-CoV-2 pandemic worldwide, independently of the viral variant involved. Evidence points to a key role of superspreading in the success of VOC. Studies analyzing selective forces on VOC should not ignore the power of genetic drift on spreading.