Lockdown Restrictions Prevented 60 Million Coronavirus Infections, New Study Says

Coronavirus lockdowns and large-scale shutdown methods such as stay-at-home orders and closing schools likely prevented 60 million more COVID-19 cases across the country, a new study suggests. The study, published Monday in the scientific journal Nature, looked at the efficacy of shutdown policies in China, South Korea, Italy, Iran, France and the United States.

What the study found was that without certain policies implemented in these countries at the start of the pandemic in January through early April, there would be roughly 285 million more total infections in China, 38 million more in South Korea, 49 million more in Italy, 54 million more in Iran, 45 million more in France and 60 million more in the United States — suggesting the emergency COVID-19 responses prevented more than 500 million total coronavirus infections across the six countries.

The study's lead author, Solomon Hsiang, a professor and director of the Global Policy Laboratory at the University of California, Berkeley, noted in a press release that the study ended on April 6, so there have likely been even more infections avoided in the shutdown days to follow.

"The last several months have been extraordinarily difficult, but through our individual sacrifices, people everywhere have each contributed to one of humanity's greatest collective achievements," Hsiang said in the press release. "I don't think any human endeavor has ever saved so many lives in such a short period of time. There have been huge personal costs to staying home and canceling events, but the data show that each day made a profound difference. By using science and cooperating, we changed the course of history."

The study does not estimate how many deaths could have been prevented, the researchers noted in the study, which would require "additional modeling approaches because they are relatively more context- and state-dependent." There were additional limitations to the study, including limited available data on infections and measures across some countries and the inherent limitations of estimation.

"Our empirical results indicate that large-scale anti-contagion policies are slowing the COVID-19 pandemic," the researchers wrote. "Because infection rates in the countries we study would have initially followed rapid exponential growth had no policies been applied, our results suggest that these policies have provided large health benefits." As of Tuesday, Johns Hopkins University had recorded 7,151,267 total coronavirus cases worldwide and 407,067 deaths, more than 111,000 of which occurred in the U.S.