States around the US are starting to open up after a few months of stay-at-home orders, and a new study from the University of California, Berkeley, suggests that such safety measures significantly stopped the spread of the novel coronavirus (COVID-19). Researchers examined six countries — China, the US, France, Italy, Iran, and South Korea — and estimated how 1,717 policies on the local, regional, and national levels like travel bans, stay-at-home orders, and closure of businesses thwarted the spread of the virus. The results? Those countries managed to avoid 62 million confirmed cases of COVID-19, including 4.8 million in the US through early April.
Cumulatively, these policies prevented or delayed an estimated 530 million total infections of COVID-19 across those six countries and 60 million in the US alone. The number of avoided total infections is higher than avoided confirmed cases due to the fact that many infections, especially in the beginning of this pandemic, were not formally diagnosed, as CNBC pointed out. (Plus, the New York Times reports in its own data that confirmed cases are widely considered to be an "undercount" of total infections.) For this study, stats from the US were used from March 3 to April 6.
"Our results suggest that ongoing anti-contagion policies have already substantially reduced the number of COVID-19 infections observed in the world today," the study, published as a preview online in the journal Nature on June 8, reads. "The magnitudes of these impacts partially reflect the timing, intensity, and extent of policy deployment (e.g., how many localities deployed policies), and the duration for which they have been applied."
Without the restrictions put in place by these countries, the Berkeley researchers estimated that the early infection rates of COVID-19 would have grown 43 percent per day on average across the six countries and 34 percent per day in the US. This implies that the number of infected people would have doubled around every two days, the study states.
It's important to note that the US specifically has 1.9 million COVID-19 cases so far and still surpassed the 100,000 death toll the pandemic was first reported. Additionally, this study does not estimate how many deaths might have been prevented. However, researchers want these findings to 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."
According to CNN, Professor Solomon Hsiang, director of the Global Policy Laboratory at the University of California, Berkeley, said in a press release, "There have been huge personal costs to staying home and canceling events, but the data show that each day made a profound difference."