COVID-19 Conversations A Webinar SeriesWhen it comes to COVID-19, there are still a lot of unknowns about the devastating disease. But public health officials know they have at least one proven intervention that can help stop its spread: social distancing.

As scientists around the globe race to develop vaccines and treatments against COVID-19 — which, as of March 29, had infected almost 635,000 people worldwide, leading to 30,000 deaths — public health officials are urging people to stay apart and stay home.

That strategy, of physically distancing from one another, can significantly “bend the curve” of disease transmission, according to Nancy Messonnier, MD, director of the Centers for Disease Control and Prevention’s National Center for Immunization and Respiratory Diseases.

Nancy MessonierMessonnier joined a panel of experts on March 25 for “The Science of Social Distancing, Part I,” a webinar organized by APHA and the National Academy of Medicine. Viewed live by about 10,000 people, the webinar shared findings on social distancing and showed how they could be applied to the ongoing pandemic.

If we decrease personal interactions, we decrease the ability of the virus to spread,” Messonnier said. “There is a lot of science on this, and we know that the measures work.”

To support social distancing, schools, businesses, transportation, parks and even roads have been closed across the U.S. Many Americans have heeded calls from health officials to stay home from school and work and avoid gathering together in groups.

“People are actually listening to the guidance to restrict movement and implement nonpharmaceutical inventions in a dramatic way,” Messonnier said.

But even as people across the U.S. hunkered down in hopes of staying safe from the disease, policymakers debated how soon restrictions could be lifted and businesses and schools reopened. Those decisions should not be made lightly, advised Howard Markel, director of the Center for the History of Medicine at the University of Michigan, during the webinar.

Howard MarkelJust as history has shown that social distancing works, it also shows that lifting restrictions prematurely is a mistake, he said. Once non-pharmaceutical interventions such as social distancing begin, “you have to have the patience to see it through.

“If you end them too soon, it won’t reduce cases or stop the flood of patients to hospitals,” Markel said. "Too early and not only will the circulating virus do what it naturally does, but all the economic and social disruptions are for nothing.”

Among those who had favored lifting the restrictions early were President Donald Trump, who had been calling for an end by Easter. But on March 29, following reports from advisors that as many as 200,000 people in the U.S. could die from COVID-19, Trump said that guidelines to practice social distancing and other measures would stay in place through April 30.

That timeframe may give public health and medical officials enough time to put other interventions in place, such as better surveillance, more intensive care capacity and other measures.

Marc Lipsitch“If you get transmissions down enough with social distancing, other interventions become more practicable,” said Marc Lipsitch, director of the Harvard T. H. Chan School of Public Health’s Center for Communicable Disease Dynamics. “We have to deal with a problem that looks small now in order to avoid, three weeks or four weeks later, consequences of growing demand for intensive care and hospitalization.”

Though, as Messonnier noted, many people were heeding warnings to stay apart and stay home, others have not. In recent weeks, national parks have reported a flood of visitors, and beaches have been crowded with students on spring break. After people ignored warnings to stay apart in Washington, D.C., officials closed roads to try to keep crowds from visiting the city’s famous cherry blossoms. 

Mitch StriplingOne way to get more people to support social distancing is to present it in language that they understand. For example, telling people to stay home and stay six feet apart is clearer than telling people to “social distance,” noted Mitch Stripling, national director of emergency preparedness and response for Planned Parenthood Federation of America.

“We’re talking about ‘nonpharmaceutical interventions,’ ‘social distancing’ — all of that language comes with scientific baggage,” he said. “We need to learn a new vocabulary.”

Comparison of less clear and more clear language about social distancing


The March 25 event was the first in a new series of rapid-response webinars from APHA and the National Academy of Medicine, called COVID-19 Conversations. Watch a recording of “The Science of Social Distancing, Part I” online now.

Save the date for “The Science of Social Distancing, Part II,” which will be held April 1 from 5-6:30 p.m. ET.

Photos, from top: Nancy Messonier, Howard Markel, Marc Lipsitch, Mitch Stripling, and a snapshot of one of Stripling's webinar presentation slides