Do Masks Work For COVID-19?

The question we’re still somehow debating

When I first wrote about masks in 2020, there were no stock photos. Look at the progress! Photo by Mika Baumeister on Unsplash

Masks are, for many, one of the most contentious issues of the pandemic. While in theory they are just small scraps of fabric that you wear on your face, for many masks have become a symbol of either the wish to protect people from COVID-19 or a refutation of the mainstream approach to controlling infectious disease.

Which is weird, because when push comes to shove it’s some material on your face, not a massive political statement.

Pictured: Just not that big of a deal. Photo by Anastasiia Chepinska on Unsplash

However, because they’re such a hot-button topic, there has been a huge debate over masks during the last few years. Do they work? Which mask is best? Should governments adopt policies that promote or even mandate masks to prevent cases of COVID-19?

And recently, this has all come to a head with the publication of a new study that, for some, seems to have answered the question forever. The lead author of this paper has publicly written that it shows that masks have “no effect” on lab-confirmed COVID-19 cases, and this has been taken up by innumerable people online to declare that masks are a complete waste of time when it comes to pandemic disease.

However, on the other hand you’ve got many people arguing the precise opposite — that this new study was completely inappropriate, and that masks clearly work so well they prevent almost all cases of COVID-19.

I disagree with both of these perspectives. Overall, I would say that the evidence shows quite convincingly that population-level mask interventions in the community have a real but modest benefit on the spread of COVID-19. In other words, neither a silver bullet nor a travesty.

Let’s look at the science.

The Science

The new study that has everyone up in arms is an update to a large systematic review which covered various physical interventions implemented against respiratory viruses. In practice, this mostly means that the authors aggregated together the results of all the studies looking at masks or hand washing, and whether these interventions…