This is actually a perfect example of the difficulty of scientific communication to a large audience. You need to communicate concise easy to understand guidance about complex topics. Asking “are masks effective” isn’t a simple question and the answer is, it depends. The first part is “effective at what task”, the second is “to what extent”, third is “in what situation”, fourth is “with what risks and tradeoffs”. I’ll be talking about the non-N95 masks unless specifically stated, to avoid any confusion.
Masks are not very effective at preventing an uninfected person from contracting Covid when in proximity to someone infected with Covid. The masks do not form a seal around the mouth and nose, allowing significant amounts of air around the mask when breathing in, as well as not being able to prevent being infected through the eyes. They do provide some protection, including possibly reducing the severity of the infection if contracted while wearing the mask, but that is not their primary benefit.
Mask are effective at preventing the spread from an infected person (either asymptomatic or symptomatic) to others. Breathing out directly into a mask allows the material to catch and trap the majority of the virus carrying condensation, and what gets out around or through the mask is slowed down significantly, allowing the droplets to be pulled down by gravity before traveling as significant distance (or fog up your glasses). Especially when combined with social distancing, this is very effective at prevent the spread of the virus. This is the masks primary benefit and is effective when there is large scale adoption, so that people that have the virus but are not aware, don’t unknowingly pass it. Its effectiveness comes as an aggregate effect similar to herd immunity, rather than an individual effect, since the vast majority of transmission comes from people unaware they are carriers.
Mask come with risks. People tend to touch their face more while wearing masks, and contracting the virus by touching your face is a primary infection mode. People tend to relax other more effective protection methods when wearing a mask, both unconsciously and due to a false belief in the protective capabilities of a mask.
So, in March we had a situation where we were running a shortage of masks. We had people wearing masks (either homemade or surgical) because they believed the mask provided good protection from contracting the virus, which is not true, and may cause people to engage in risky behavior that would put them and others at more risk. We also didn’t have enough masks to be used for their actual benefit of “herd immunity”. The assessment was that non sick people wearing masks was likely to put the individual at greater risk, and deplete the resource from places it was needed, without providing a medical benefit to the individual greater than the risks. In March, the average non sick person should not be wearing a mask.
After several months, we had a situation where we did not have a shortage of masks. We had a situation where the public has been educated through awareness campaigns on how masks work, like the “My mask protects you. Your mask protects me” campaign, so people are less likely to use the masks incorrectly and put themselves and others at greater risk. The assessment is that high compliance of mask wearing will have a greater positive effect through “herd immunity” to outweigh the risks and tradeoffs. But make no mistake, the risks are still there. In that case, the average non sick person should be wearing a mask.
If you don’t understand the underlying medical complexities of the situation, it seems like they can’t both be true. And when an expert organization is trying to provide a clear, short, easy to understand list of recommendations from analyzing and evaluating all those data, they can’t go into to a 45 min presentation every time. Dr. Fauci even tried to add context in March. He talked about how the masks don’t provide protection in the way people think they do, how it can cause people to put themselves at greater risk, both through a false sense of protection and other behaviors like face touching, and how masks primarily protect you from infecting others, not the other way around. If you go back and look at his quotes at the time, he consistently tries to bring that additional context into it, but since it is a complex issue of competing risks and benefits, it’s hard to convey how masks can be good in some cases and bad in others.
> Dr. Fauci in March 2020. “When we get in a situation where we have enough masks, I believe there will be some very serious consideration about more broadening this recommendation of using masks. We're not there yet, but I think we're close to coming to some determination. Because if, in fact, a person who may or may not be infected wants to prevent infecting someone else, one of the best ways to do that is with a mask, so perhaps that's the way to go.” [1]
> And of course his 60 Minutes interview. “There’s no reason to be walking around with a mask. When you’re in the middle of an outbreak, wearing a mask might make people feel a little bit better and it might even block a droplet, but it’s not providing the perfect protection that people think that it is. And, often, there are unintended consequences — people keep fiddling with the mask and they keep touching their face.”
[1] https://www.axios.com/anthony-fauci-masks-coronavirus-f77c30...