"This means at least half of new infections come from people likely unaware they are infectious to others." The CDC explains that 24% of coronavirus transmitters are asymptomatic, 35% presymptomatic, and 41% were experiencing symptoms.

Led by experts in the US and Canada, it was based on "recent individual-level data" showing that "the majority of incidences may be attributable to silent transmission." It added that "consequently, even if all symptomatic cases are isolated, a vast outbreak may nonetheless unfold," and "over one-third of silent infections must be isolated to suppress a future outbreak below 1% of the population." The CDC concludes that people can help curb the virus by wearing masks, washing their hands, cleaning and disinfecting surfaces, using ventilation, and avoiding crowded indoor spaces