Study Calculates COVID-19 Incubation Period

Stephen Lauer '19PhD

March 13, 2020

A new study by recent biostatistics doctoral alumnus Stephen Lauer ‘19PhD, a former member of the Reich Lab and current postdoctoral researcher at the Johns Hopkins Bloomberg School of Public Health, calculates that the median incubation period for COVID-19 is just over 5 days, and that 97.5 percent of people who develop symptoms will do so within 11.5 days of infection. The incubation period refers to the time between exposure to the virus and the appearance of the first symptoms.

Lauer, along with co-authors including his former mentor Nicholas Reich, associate professor of biostatistics in the UMass Amherst School of Public Health and Health Sciences, examined 181 confirmed cases with identifiable exposure and symptom onset windows to estimate the incubation period of COVID-19. They conclude 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.”

The study appears in the Annals of Internal Medicine.

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