What we know about asymptomatic transmission, immunity and COVID-19

A researcher works in a lab that is developing testing for COVID-19
A researcher works in a lab that is developing testing for the COVID-19 coronavirus at Hackensack Meridian Health Center for Discovery and Innovation in Nutley, N.J.
Kena Betancur | Getty Images file

An interesting facet of the novel coronavirus is how seemingly healthy people transmit the virus to others through asymptomatic spread. Not to be confused with pre-symptomatic transmission, it’s estimated by the Centers for Disease Control that about 40 percent of people infected with COVID-19 have no symptoms — ever.

We’re also learning more about our immune response to the virus. Early research points to a strong immune response, even in those who only showed mild symptoms.

MPR News host Kerri Miller talked with a doctor and immunologist about what we know about transmission, immunity and antibody response and testing.


  • Dr. Monica Gandhi is a professor of medicine and associate division chief of the Division of HIV, Infectious Diseases, and Global Medicine at UCSF/San Francisco General Hospital.

  • Jennifer Gommerman is a professor of immunology at the University of Toronto’s Faculty of Medicine.

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