A new study found that social distancing worked to limit the spread of coronavirus in the United States and may have prevented tens of millions of infections.
The study, published Thursday in the journal Health Affairs, found that government-imposed social distancing cut the virus’ daily growth rate by about 9% after roughly three weeks.
Without any social distancing measures at all, the number of coronavirus cases in the US could have been 35 times higher, the researchers estimated.
“Our paper illustrates the potential danger of exponential spread in the absence of interventions, providing relevant information to strategies for restarting economic activity,” they wrote.
Charles Courtemanche from the University of Kentucky — as well and colleagues there and at the University of Louisville and Georgia State University – estimated the effects of social distancing by comparing coronavirus cases in counties with and without a number of social distancing measures.
Shelter-in-place orders and the closure of restaurants and bars seemed particularly effective at slowing the spread of the virus, the researchers found. Bans on large events and the closure of public schools alone didn’t seem to affect the growth rate.
“[Our] results argue against returning to partial measures such as school closures and restrictions on large gatherings, while removing the restrictions that prevent the redirection of social activity to other settings,” the researchers wrote.
They did note that their study had some limitations. Official case counts, for example, are likely an undercount because they may not include people who aren’t sick enough to go to the doctor.
Other factors could have skewed the results too, such as “informal encouragement by government officials to wear masks or improve hygiene, changing business practices, and social norms regarding distancing.”