'Flatten The Curve': How Social Distancing Can Slow The Spread Of Coronavirus

Because of the threat of transmission of the novel coronavirus (COVID-19), the Pentagon is exercising social distancing by keeping reporters' chairs four feet apart from each other during briefings. (Chip Somodevilla/Getty Images)
Because of the threat of transmission of the novel coronavirus (COVID-19), the Pentagon is exercising social distancing by keeping reporters' chairs four feet apart from each other during briefings. (Chip Somodevilla/Getty Images)

This segment is part of this hour here. Audio will be available here after broadcast.

Social distancing is being encouraged as a way to slow the spread of the coronavirus. We’ll talk about 'flattening the curve.'


Dr. Bill Hanage, associate professor of epidemiology at the Harvard T.H. Chan School of Public Health. Author of the Washington Post article "If you can work from home, you should. Now." (@BillHanage)

Interview Highlights

When we say 'flatten the curve,' what curve are we talking about? 

Dr. Bill Hanage: "We're talking about the epidemic curve. Infectious disease outbreaks tend to follow a fairly predictable pattern, if you can understand the mathematics of it well enough. You get the data on that early on. What you see is you see a rapid increase in the number of cases. And then if it continues without any intervention, will only start to decrease once enough people are immune. What we're trying to do in 'flatten[ing] the curve' is to slow the rate of increase."

"Essentially at the start, it's always going to be exponential and we should be intervening now to try and make it less steep."

Dr. Bill Hanage

That initial rate of increase, if there are no protective measures put into place for an epidemic, is it typically sort of an exponential increase? Is it ever linear? 

Dr. Bill Hanage: "There's always going to be an exponential feature to this because of the fact that the way that infectious diseases spread. It will get more complicated as time goes on because of the fact that, among other things, people change their behavior. And also, among other things, you can't always be infected. You can't be infected more than once. ... If you've been infected by one person, the contact from another person doesn't count in quite the same way. So essentially at the start, it's always going to be exponential and we should be intervening now to try and make it less steep."

On why people should work from home if they can

Dr. Bill Hanage: "You want to break the chain. And I wrote that because of the fact that I started working from home and I was thinking about my lab manager who was not able to work from home. And I figured, you know, the best thing I can do to help her and to help all the people I know who are unable to do that right now is to ensure that I don't become infected and transmit to any of them. To ensure that I at least delay myself becoming infected and entering the health care system and becoming a burden.

"And so if you can do it, then I think that you should. I mean, I understand that not everybody can. I really get that. And these are part of a whole range of other measures which should be put in place. Which include support for people, you know, good sick pay. Understanding that employees should probably be staying home if they have had contact with a case, as well. Because anything that you can do to slow it down, anything you can do to avoid being Italy, is something which we really should be doing now."

On China's response to coronavirus and the importance of social distancing 

Dr. Bill Hanage: "I think that we have a lot to learn from China. But I also think that we've got to recognize that there are large differences between China and the United States. This is why I think that the most important thing to do is to get as much information out on social distancing across the country, as early as possible. Prepare people for the disruption that their lives are going to be suffering. Prepare people for the fact that it's not just possible that you will see closures of workplaces and possibly schools. At some point, it's likely. So you should be prepared to be taking those outcomes. And I think that we've been taking a good few steps in the last few days and weeks. And I'll be honest, I haven't even had time to keep track of the news because basically my attention is consumed with this global pandemic. The earlier that we can take steps, the better."

From The Reading List

The Washington Post: "If you can work from home, you should. Now." — "The fire is upon us. By now, the SARS-CoV-2 virus is either established or making itself at home in communities across the United States. This is a fact. We are all at risk of infection right now, some more than others, depending on where they live or the jobs they do. And it is only going to get worse.

"If you don’t believe me, just wait for the report of the first case in your neighborhood. That’s coming, if it hasn’t happened already. Case counts are going to tick up across the country. While we expect the great majority to suffer only mildly, some people will get much sicker, and there will be deaths. Covid-19, the disease caused by the novel coronavirus, doesn’t seem to kill quickly, so it might take a while, but they are coming. Less than three weeks ago, Italy was reporting 121 cases. On Monday, authorities there put travel restrictions on the whole country, affecting 60 million people, until April 3.

"So what we need to do now, before things get really bad, is think about how to protect the health-care systems we rely on and keep them from being overwhelmed by a surge of cases, as is already happening in Washington state."

The Washington Post: "Why outbreaks like coronavirus spread exponentially, and how to 'flatten the curve'" — "After the first case of covid-19, the disease caused by the new strain of coronavirus, was announced in the United States, reports of further infections trickled in slowly. Two months later, that trickle has turned into a steady current.

" ... This so-called exponential curve has experts worried. If the number of cases were to continue to double every three days, there would be about a hundred million cases in the United States by May.

"That is math, not prophecy. The spread can be slowed, public health professionals say, if people practice “social distancing” by avoiding public spaces and generally limiting their movement.

"Still, without any measures to slow it down, covid-19 will continue to spread exponentially for months. To understand why, it is instructive to simulate the spread of a fake disease through a population."

Wes Martin Freelance Producer
Wes Martin is a freelance producer for On Point.


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Meghna Chakrabarti Host, On Point
Meghna Chakrabarti is the host of On Point.



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