Another study estimated that the shutdowns saved about 3.1 million lives in 11 European countries and dropped infection rates by an average of 82 percent. Both reports were published Monday in the journal Nature. The two reports provide fresh evidence that aggressive and unprecedented shutdowns, which caused massive economic disruptions, were necessary to halt the exponential spread of the novel coronavirus. The first study, from researchers at the University of California at Berkeley, examined six countries — China, the United States, France, Italy, Iran and South Korea — and estimated how 1,717 different interventions, such as stay-at-home orders, business closings and travel bans, altered the spread of the virus. The report concluded that those six countries collectively managed to avert 62 million test-confirmed infections, which the researchers estimate would correspond to roughly 530 million total infections.