The World Health Organisation announced new guidance on masks late last week, spurring another wave of eyerolling about how “they” keep changing their minds. Previously the WHO did not recommend that healthy people wear masks; now they say that people over 60 and people with underlying health conditions should wear masks where distancing is not possible. They also say that local governments in the U.S. may want to recommend masks for everybody, but that they leave it as a judgment call for those officials.
Throughout this pandemic, messages about masks—including who should wear them, and what kind—have seemed contradictory. But a lot of the important points have never changed.
What does change, though, is our understanding of which facts are most important, and how the harms and potential risks balance against benefits. Back on February 7, for example, we published a post asking you to quit buying coronavirus masks you don’t need. This was, again, a recommendation from the World Health Organisation that was being echoed by other public health organisations. The information in that post is still true, but the emphasis on what’s important has changed.
At that time, there were only 12 known cases of the coronavirus in the whole U.S. If you weren’t one of those cases (or a close contact), the thinking was that you were very unlikely to be already infected. Meanwhile, medical masks were in short supply worldwide. Remember what happened with toilet paper? It was important to head off panic buying. And with such a small number of cases in a small number of cities, it was true that most people did not need masks.
What’s changed since then? Mainly these things:
Community spread in the U.S.
First, testing didn’t keep up well enough to allow surveillance of where the virus actually was. To get a test in early 2020 required that you be a contact of someone who had the virus or was highly likely to have it, which means that community spread could not possibly be detected. That was a fuckup. And once we realised that, the overall shortage of tests was another fuckup. By the time we realised there was community spread, it was far too late to track down every case and their contacts.
With untracked community spread, it was no longer possible to tell people that they were unlikely to encounter the virus in the wild. We didn’t know.
It also took time to learn that people could spread the virus without showing symptoms. Experts still debate how common asymptomatic (or presymptomatic) spread is, but we now know that it can happen. A big part of the reason for masks is that they prevent you from spreading the virus that you don’t yet know you have.
There has been, and still is, a shortage of personal protective equipment for healthcare workers. If anybody needs a mask in a pandemic, it’s them. Healthcare workers come into contact with people who have (or might have) COVID-19, and they can spread it to others. For their own health, and for the health of patients and the community, it makes sense to prioritise healthcare workers.
That’s why, in a March 8 interview, Dr. Anthony Fauci said that “right now, in the United States, people should not be walking around with masks.” In the clip, he goes on to say that wearing a mask isn’t harmful, but “it’s not providing the perfect protection that people think it is” and that widespread mask wearing could contribute to the ongoing shortage.
That was all true, and it’s still true. Mask sceptics have been sharing this clip ever since, either to give people the idea that masks aren’t currently recommended (by hiding the fact that the clip is old) or to make Fauci or the CDC look like hypocrites. But the underlying facts haven’t changed.
Fabric masks shifted the balance
If medical masks aren’t available, are fabric masks good enough? That’s the question that policy makers and public health organisations debated for weeks.
There’s still not a clear answer. Fabric masks are not as good as medical masks, but they probably still provide some protection. Is a society better off, overall, when mask wearing is common? That’s also still unclear. Probably fewer people are breathing out droplets of virus. Probably people aren’t making the situation too much worse by touching their masks and by getting too close to others under the mistaken belief that masks protect them.
As much as we’d like all our decisions to be based in science, this one is still a judgment call. One fortunate change is that we turned out to be capable of making and distributing a huge number of fabric masks. People who sew made masks for themselves and friends; clothing companies started churning them out. Pretty soon it wasn’t too hard to get a mask, and not too onerous to expect people to be able to obtain them.
Here’s what hasn’t changed
Through this whole timeline, several things have been true, and remain true:
Both fabric and surgical masks are most useful as source control (on the infected person), rather than protecting you from other people.
Fabric masks don’t work as well as surgical masks.
There’s still a shortage of surgical masks and respirators (N95s), so if you aren’t a healthcare worker, it’s probably best to stick with fabric masks.
Masks are not perfect protection, and only make sense in addition to distancing and other protective measures.
So even though mask guidelines have shifted, the important things are all still true. You should still stay home when you’re sick, and keep your distance from people as much as possible. For our current time and place, it makes sense to wear a fabric mask when you can’t maintain distancing from other people. And if the guidelines change again, don’t be too surprised. We should expect guidelines to change as we learn more and as the situation changes.