Submitted by the Whatcom County Health Department
Did you know that a family of mice can increase to over 100,000 mice in a single year? Now: imagine that the first two mice never met. That’s a difference of 99,998 mice.
COVID-19 can work like this, too. Preventing a single new infection can make a huge difference over time.
This is a community challenge though, so it helps to look at it from a larger perspective. One thing we’ve learned is that mask use seriously reduces transmission rates, perhaps by as much as 50-75%. And if that’s the difference between ten infected people transmitting the virus to 14 others – or just seven, it means a lot.
No one has a crystal ball. But even though models and estimates are essentially “educated guesses,” that education is based on a growing amount of research, and the math used is tried and true. Now that we can look back at what has happened over the last three months, there is good reason to believe the models are on track. An estimate from the Institute for Health Metrics and Evaluation predicts that wearing masks is 50% effective, or in other words, will prevent half of the new infections. If masks can block 50% of new infections, and 95% of people wear them for the next three months, this would reduce the state’s estimated daily infection rate on October 1 to less than 250 new cases. Without masks? Then the model predicts that we’ll see 2,400 new cases on that day. Yes, 2,400 cases in just a single day. And the deaths will increase too, from a single death (if masks are worn) to 11 deaths that day (if masks are not worn).
A local model, developed in Whatcom County, used a different estimate to explore the impact of wearing masks. This model assumes a 75% effective rate for masks (masks prevent three out of four new infections) and uses info about social distancing and observed mask-wearing behaviors at local shopping centers. The study estimated that about 46% of Whatcom County shoppers were wearing masks in early June, and explored what would happen if that number increased to 80%.
It turns out, that would make a big difference. For Whatcom County, the new daily cases estimated for October 1 would be just five if masks are worn by 80% of the population.
If we continue with 46% use rates though, the predicted new daily case count is more than 1,900. These numbers make it clear that small differences early on can make a huge difference over time. A lot can happen in three months, things can change dramatically.
Wearing a mask when you’re in public is an easy way to show that you care about your community and that you want to speed up our economic recovery from COVID-19. Whether mask use is 50%, 75%, or even just 25% effective, the outcomes, three months from now, will be very different based on our actions today and tomorrow. The good news is that we can all play a part in putting COVID-19 behind us and that the solution could very well be right in front of our faces. We’re all in this together.