What is the incubation period?

The incubation period is the duration between exposure to the virus and the onset of symptoms. The World Health Organization (WHO) currently estimates that the incubation period ranges from 1 to 14 days, with a median incubation period of 5 to 6 days. These estimates will be refined as more data becomes available. The Department is aware of reports that suggest there have been cases with longer incubation periods, such as 24 days. The incubation period of infections often has a skewed distribution, where most patients have an incubation period that clusters around the average, but a few patients have a longer incubation period. Medical experts believe reports of cases with longer incubation periods are statistical outliers – while longer incubation periods are possible, they may have been reported in error, or had exposure to an unidentified case at a later date that has not been identified in a transmission chain.

According to the Centers for Disease Control and Prevention (CDC), the incubation period for the novel coronavirus is somewhere between 2 to 14 days after exposure.

According to a recent report, more than 97 percent of people who contract SARS-CoV-2 show symptoms within 11.5 days of exposure. The average incubation period seems to be around 5 days. However, this estimate may change as we learn more about the virus.
For many people especially elder people, COVID-19 symptoms start as mild symptoms and gradually get worse over a few days.