NOEL KING, HOST:
Almost 100,000 people in the U.S. have died of COVID-19. That's more, by far, than any other country. If social distancing measures had been put in place across the U.S. earlier, could some of their lives have been saved? Researchers at Columbia University devised a model to answer that question. Their analysis shows that if we'd started a week sooner, almost 36,000 fewer people would have died from the virus.
NPR global health correspondent Nurith Aizenman has been following this one. Good morning, Nurith.
NURITH AIZENMAN, BYLINE: Good morning.
KING: Thirty-six-thousand people is a lot of lives, a lot of people dead. How did researchers come to this conclusion?
AIZENMAN: Yeah. So the lead researcher, Jeffrey Shaman, has been putting together one of the more prominent disease models in this pandemic. And for this analysis, he and his collaborators used a similar approach - basically looked at the data that we have to date for each county in the United States - how many confirmed cases, how many deaths, as well as factors like how dense is the area? How do people commute to work - driving cars, taking the bus? And from all that, they estimated how fast coronavirus was spreading at various points in time. Here's Shaman.
JEFFREY SHAMAN: We get an estimate, and once we have that estimate we're able, actually, to simulate with this model the number of cases and deaths that actually did occur throughout the United States. In all the major metropolitan areas where there are lots of cases, we get it - we're able to simulate what went on nationally. Basically, we fit the model so that it's capable of representing what actually transpired.
AIZENMAN: And they found that from March 15, the rate really slowed due to people beginning to social distance in a big way - voluntarily or because of stay-at-home rules. So then they calculated, what if that behavior - and the slowdown in spread that came with it - what if that had kicked in a week earlier on March 8? They found a week makes a huge difference. We would have had 55% fewer deaths over the period through May 3. And with a two-week head start, we would have had 83% fewer deaths - nearly 54,000 lives saved.
KING: That is remarkable. On the other hand, I guess, Nurith, if you wanted to defend the way the country did things, you could say - but back in March, things seemed much less dire. We just didn't know what was going to happen.
AIZENMAN: Sure. And that's actually a limitation of this analysis because in early March, when we weren't seeing as many deaths, even if officials had taken action sooner, would people have complied to the same degree? Here's what Sherman, the researcher, had to say about it.
SHAMAN: The reality is that, you know, the United States has had a very cushy existence since World War II. We've not had a lot of things that have required a lot of sacrifice. We have not been primed for dealing with or thinking about infectious diseases.
AIZENMAN: So he says whether that would've been the political will or the public will to take action earlier is up for debate. Of course, it's worth pointing out that leaders in some countries - South Korea, Germany, New Zealand - leaders there did make the case to their citizens earlier on, and they benefited. They have far fewer cases and deaths per capita than the U.S.
KING: OK. So this model looked back at the mistakes of the past. Did it tell us anything about how we should move forward?
AIZENMAN: Yeah. And with the usual proviso that this is just one of many models out there, the researchers also ran simulations to see, now that we're opening up again, if we do have a rebound of cases, how big of a difference will it make if we act immediately or if we wait? And again, because this virus spreads exponentially, as little as a week or two can result in significantly more deaths. Here's Shaman.
SHAMAN: We have to be so responsive and so attentive to what's going on and able to quickly identify when there's a resurgence of the infection in a community and to respond to it quickly and to have the will to do so and not repeat our mistakes.
AIZENMAN: And he says for that, we will still need a much more robust system than we currently have for testing and contact tracing.
KING: OK. NPR's Nurith Aizenman. Thank you.
AIZENMAN: You're welcome. Transcript provided by NPR, Copyright NPR.