Superspreading genomes

Virus mutations help to unravel key epidemiological events Individual contributions to epidemic spread vary. Although some infections may not cause any secondary cases, others are associated with so-called “superspreading” events in which numerous infections result from the same case. These events can shape the course of an epidemic, but their detection remains challenging. On page 588 of this issue, Lemieux et al. (1) show that phylogenetic analyses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome sequence data help quantify the prevalence and impact of superspreading events on COVID-19 outbreaks.