When a person is infected with a virus, the virus multiplies in the body and can be released into the environment through sneezing, coughing or even speaking. This release is called "shedding" and viral shedding is how COVID-19 is spread from person to person. How long a person who has COVID-19 will shed virus is still unknown.

On the Mayo Clinic Q&A podcast, Dr. Gregory Poland, an infectious diseases expert and head of Mayo Clinic’s Vaccine Research Group, discusses viral shedding and why asymptomatic carriers of COVID-19 are a big concern.