A new study just published in the Annals of Internal Medicine calculates that the median incubation period is about 5.1 days. That means that in some people, symptoms of COVID-19 take longer to show up, in others they take less time. It found that 97.5 percent of people who develop symptoms will do so within 11.5 days of infection.
What that means, the study authors conclude, is that the current period of active monitoring recommended by the U.S. Centers for Disease Control and Prevention (14 days) is well supported by the evidence.
These researchers, from Johns Hopkins Bloomberg School of Public Health, the School of Public Health and Health Sciences at the University of Massachusetts, and Ludwig-Maximilians-Universitt in Munich, investigated 181 confirmed cases of infection outside the original epicenter of Chinas Hubei province.
Since this coronavirus is new, theres still much to be learned about it, and the researchers allow that the incubation period for severe cases may differ from the incubation period for less severe infections. Its hard to be certain yet, since the confirmed cases of COVID-19 in this study may overrepresent hospitalized, more severe cases. Increased testing and monitoring will likely turn up additional answers, as the proportion of mild cases that are detected grows.
For now, you know the drill: Wash your hands , monitor yourself for symptoms, know what to keep on hand , and know the facts about how it acts and what to do.