Epidemiologist Marc Lipsitch answers COVID-19 questions

In a wide-ranging Q&A, epidemiologist Marc Lipsitch discussed the coronavirus—its trajectory, the impact of social distancing on disease spread, when the U.S. can open up again, testing for COVID-19, and immunity.

The key to easing social distancing measures and getting people back to work and school will be using serologic testing—testing for antibodies to COVID-19—to determine if people have developed immunity, said Lipsitch, professor of epidemiology and director of the Center for Communicable Disease Dynamics, in an April 8, 2020 USA Today interview. Then scientists will have to determine how much protection immunity confers, and whether it varies from person to person.

“We don’t know whether it will be possible to distinguish someone who is functionally immune from someone who has an immune response that’s not protective,” he said. “That’s an open scientific question right now.”

He predicted that increasing fatigue with social distancing will prompt some regions of the U.S. to ease restrictions. Then “cases will reemerge, and … it will take until the intensive care units are overwhelmed in that place to get people to crack down again.”

He added, “There are ways to avoid that, but they all involve this very long and destructive process of social distancing. It’s easy to say as the public health person, this is what we need to do for public health. But I’m acutely aware that there are also other considerations, and I don’t see a really good answer.”

Read the USA Today Q&A with Marc Lipsitch: Coronavirus ‘is the Big One … I hope never to see bigger’: Harvard epidemiologist