What do crowded college parties, large weddings, family parties and busy bars all have in common? All of them have the potential to be superspreader events, where the novel coronavirus can be spread to a huge amount of people at once. While there is no scientific definition of a superspreader event, Winslow said that events that led to COVID-19 outbreaks have had several factors in common. "The big concern is that having lots of people jammed indoors, particularly when not wearing face coverings, is sort of a recipe for transmission of SARS-CoV-2," he said. "One of the things that I think is really well appreciated now is that things like speaking and singing will generate very small particle aerosols ... In an indoor environment, where you have less air circulation than outdoors, those particles can remain suspended in the air for several hours or so."