
One of the strangest things that has happened during the COVID-19 pandemic is the politicization and polarization of the American public. Instead of relying on science, people are relying on echo chambers of social media for their understanding of the disease. This breeds a lot of lies and disinformation. Instead of trying to pick apart the false arguments though, I’m simply going to show why the narrative makes a difference.
Sanche et al. reported that early on, the reproductive rate (R0) for the virus was thought to be 2.2-2.7. That is simply the number of people who get the disease from an infected individual. However, the authors calculated a R0 of 5.7 over a 6-9 day period. Just for the sake of argument though and to keep this simple, I’ll use a lower value of 3.0, which is below the 95% confidence interval in their report and 9 days for my illustration.
Under the above conditions, assume that something I say or write causes one person to behave differently and prevents them from getting infected. Over the next four generations of disease (36 days), and assuming that everyone downstream from that person doesn’t do anything to keep from becoming infected but isn’t exposed through anyone else, that would prevent 81 people from becoming infected. For arguments sake under the same conditions, let’s say I prevent that directly among 10 people. That prevents 810 infections. Assume I prevent 100 people initially from making mistakes. That would prevent 8100 infections, and if the case fatality rate was 1%, it would prevent 81 deaths.
On the flip side though, what if someone spreads messages that this is really not of any concern and to go about business as usual. No mask, no social distancing, going into crowds as one sees fit, etc. The opposite is then true under the same assumed conditions. That will spread the disease to 81, 810, or 8100 people. That’s why it’s so important to push science and facts as opposed to a laissez-faire approach fueled by anti-science and conspiracy theories. (For a recent examination of conspiracy theories in the US, there is a great episode of Frontline titled “United States of Conspiracy.”)
I was working on an illustration for this, but then wondered if there was something online that would do it better than I could. Fortunately, not only did I find an illustration, but an animated tool that shows just how quickly exponential spread happens and how social measures prevent spread. At the bottom of this article, you can find a tool to let you simulate spread in a population and set the values of R0, fatality rate (the percentage of people that will die), susceptibility (the percentage of people who are not immune), and isolation (which is social distancing and mask use for all practical purposes).
Set the R0 to 3, the fatality rate to 1%, the susceptibility to 100% (that’s why it’s called a “novel” virus), and see what happens with various approaches to isolation. It’s pretty stunning how quickly it spreads through 1000 people if you set that to zero.
I’ve been accused of all kinds of crazy things, such as deriving joy from watching this unfold and fear mongering. Nothing is further from the truth. I have had many sleepless nights since February as this has been unfolding.
If those assumptions were true, would I have spent much of my career working on prevention of pandemic impacts and writing here to try to get people to take it seriously? I think that a number of Americans have gone completely mad, including many I know personally.
Even then, I still want to mitigate their risk, even though I feel like I’m constantly beating my head against a wall.