Study: Lockdowns, Restrictions Averted 60 Million Coronavirus Infections in U.S.

IN JUST ONE MONTH, lockdowns and other social restrictions averted an estimated 4.8 million confirmed coronavirus cases and 60 million infections overall in the U.S., a new analysis shows.

The study, published Monday in the journal Nature, offers the latest evidence that despite widespread economic fallout, measures like stay-at-home orders and business closures were critical to curbing the exponential growth of the coronavirus in the U.S. Early on in the pandemic, infections were rising at an estimated rate of roughly 34% per day, the report shows – a level that slowed significantly after various restrictions were put in place.

“Societies around the world are weighing whether the health benefits of anti-contagion policies are worth their social and economic costs,” study authors from the University of California–Berkeley said.

Researchers sought to quantify those health benefits by measuring how the daily growth rate of infections changed from early March to April 6 as about 1,200 local, regional and national policies were adopted in the U.S., including travel restrictions, stay-at-home orders, work-from-home policies and school and business closures.

Together, these policies slowed the average rate of new coronavirus infections by about 32% per day.

That corresponds with an estimated 4.8 million people who would have been confirmed with COVID-19 had the U.S. not enacted any of these policies – a level 14 times higher than it was. And because many infected people haven’t been tested, the actual number of averted infections is likely even higher, at an estimated 60 million, researchers said.

The study also tracked the effectiveness of restrictions in China, South Korea, Italy, Iran and France. Across all six countries, interventions prevented or delayed some 62 million confirmed cases, or about 530 million total infections.

“I don’t think any human endeavor has ever saved so many lives in such a short period of time,” Solomon Hsiang, the study’s lead author and director of the Berkeley Global Policy Laboratory, said in a statement. “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 researchers noted some of the study’s limitations: While the analysis accounts for changes in COVID-19 testing, “unobserved trends in case-detection” could affect the findings. They didn’t track hospitalizations or deaths across the countries, either, so it’s unclear how many lives were saved by these measures. The study also could be attributing steps people took on their own to reduce their exposure to the virus to the policies enacted during this timeframe.

Still, “these findings may help inform whether or when these policies should be deployed, intensified, or lifted, and they can support decision-making in the other 180+ countries where COVID-19 has been reported,” researchers said.