When the novel coronavirus infects a person, it invades their cells to make more viruses. These new viruses are expelled or “shed” from the invaded cells into the rest of the patient’s body, and those new viruses make them sick. These viruses also make their way into saliva, mucus, or stool and are “shed” from the body. This is how the virus spreads from person to person, and “viral shedding” is often used as a marker of whether a person can spread the virus.
The extent of viral shedding varies throughout the course of the disease and is different for each infected person. According to the CDC, viral shedding is greatest when a person first experiences COVID-19 symptoms. But shedding can begin before symptoms emerge, and it may continue for up to several weeks after those symptoms go away. Studies of influenza and other diseases have shown that children are more likely than adults to shed virus before symptoms start. But we don’t yet know whether that is true for COVID-19.
As scientists learn more about viral shedding and what it means for COVID-19 transmission, you can help limit its spread with social distancing and good hand hygiene.
Last updated: April 24, 2020 at 2:30PM et
Science review: ERS, GSN