Monday, June 08, 2020

LOCKDOWNS HAVE WORKED TO CONTROL THE CORONAVIRUS--BUT ARE THEY WORTH IT?

If, as you've spent endless hours at home the last few months, you've wondered if the lockdowns and shelter-in-place policies that have upended lives around the world actually work, two major new research papers pretty much close the case.


Image credit: Prachatai/Flickr

Research teams at Imperial College, London and the University of California, Berkeley, used different methodologies to study the impact of the "non-pharmaceutical interventions" such as business closings, social distancing and home isolation that were put in place in different mixtures and different times in 11 European countries, and in China, South Korea, Iran and the United States.

The detailed findings are complex, but the bottom line is simple: lockdowns worked whenever and wherever they were applied. When implemented and followed consistently, within three weeks they successfully reduced the reproduction rate of the coronavirus below the critical number 1, flattened the curve of cases, and saved large numbers of lives.

The numbers that the two research teams calculated are impressive. The Imperial College team estimates that in Europe the lockdown and social distancing measures put in place in March prevented several hundred million Covid-19 cases and approximately 3.1 million deaths before the May 4 end of their data gathering.

The Berkeley group found that in the six countries they studied--including the US--the measures put in place prevented 62 million confirmed cases or an estimated 530 million actual cases.  
Assuming a case mortality rate of just one percent, that means that some 5.3 million lives were saved, again in the course of a few months.

"The lockdowns had a very large effect on cases and saving lives," says Solomon Hsiang, at the University of California, Berkeley.      "[Some people assert that] the lockdowns weren't necessary. This research nails that it was. Without them, we believe the toll would have been huge."

Researchers from both groups emphasize that some mixture of these life-changing but also life-saving measures needs to be continued, tailored to each country or region's population structure and economic needs. 

"We're just at the beginning of the pandemic," says Samir Bhatt, at Imperial College. "We're very far from herd immunity and the risk of more waves of the virus is very high. Care must be continued until a vaccine becomes available."

These two papers were published on June 8, at which point there have been more than 7 million confirmed cases of Covid-19 and 407,000 confirmed deaths worldwide. If most of the countries in the world had not taken the stringent steps they did to control the SARS-CoV2 virus, these two research papers show that those numbers would have been orders of magnitude higher.

Was it worth it? Clearly that's not a scientific question, nor should it be strictly an economic one. The answer depends on the value one places on human lives as well as on other important factors such as employment and economic well being. Both research teams are well aware of the huge economic impacts of lockdowns, social distancing, travel restrictions, business closures, and other measures taken to control the spread of the virus. But both of them emphasize that some mix of these measures will be needed for a long time. 

"There's no back to normal," says Hsiang. "It's a cost-benefit question--interventions of different kinds along with economic well-being. The longer you stay in lockdown, the fewer infections. If you undo lockdown, there's economic growth but more infections and death. Something still needs to be in place."

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You can download the full scientific papers from the journal Naturehere and also here.

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