Dec 16 2021

Mask Up

The COVID-19 pandemic is not done with us yet. We are still in the middle of the delta surge, and while delta will eventually pass, the omicron variant is right on its heels. In the US we just passed the milestone of 800,000 people dead from COVID with over 50 million cases. More Americans died of COVID in 2021 than in 2020, although in 2021 most deaths were among the unvaccinated. The vaccines remain our best defense against this pandemic, which is why it is tragic that there are still holdouts for tribal or ideological reasons. Regardless, it is extremely likely that we will be dealing with COVID through 2022. It is also likely that COVID is now endemic, and while it may fade down to flu-like proportions, we will also very likely have to deal with it for years to come. COVID is also likely not the last respiratory pandemic we will have to deal with this century.

All of this is why masks are still important. We just have to accept the fact that face masks are now an important part of life. At least for the foreseeable future we will need face masks as a layer of protection in health care settings, large indoor crowds, among vulnerable populations, and for anyone who is symptomatic. Walking around in the public maskless, sneezing and coughing from a “cold” is no longer socially acceptable. If you want to avoid the mask in small or outdoor crowds and in gatherings of family and friends, then get fully vaccinated. But even then, there are some situations where masks provide an extra needed layer of protection.

There are at least two important questions relating to mask wearing. The first is – do they really work? The short answer is yes, they do. But obviously there is some complexity here. When worn properly, and in the right setting, masks provide a measurable level of protection from a respiratory infection. They protect you and they protect others. The latest evidence to support this conclusion looked at countries with and without face mask policies. They found:

Average COVID-19 mortality per million was 288.54 in countries without face mask policies and 48.40 in countries with face mask policies.

The data also show that COVID spread faster in countries without a face mask policy. This is observational data so there may be confounding factors, but a real protective effect from masks is the simplest conclusion, which is also supported from other independent lines of evidence. If we accept the overall efficacy of face masks then the next question is – which masks work best? If we are going to bother wearing masks, they might as well work. By now everyone should know the basics. Don’t let the mask fall below your nose, don’t have wide gaps at the sides, don’t use thin or single-layer masks. Fitted N95 masks are the best, especially at protecting the wearer, followed by non-medical grade KN95 masks, medical masks, then multi-layer cloth masks.

A recent study directly compared different ways of wearing masks to provide some further guidance. They found:

Medical masks without modification blocked ≥56% of cough aerosols and ≥42% of exhaled aerosols. Modifying fit by crossing the earloops or placing a bracket under the mask did not increase performance, while using earloop toggles, an earloop strap, and knotting and tucking the mask increased performance. The most effective modifications for improving source control performance were double masking and using a mask brace. Placing a cloth mask over a medical mask blocked ≥85% of cough aerosols and ≥91% of exhaled aerosols. Placing a brace over a medical mask blocked ≥95% of cough aerosols and ≥99% of exhaled aerosols.

This matches the CDC’s current guidelines. If you are wearing a medical mask, the easiest step to improve performance is to tie the earloops (see the CDC link for images). It is also easy to simply double mask – medical mask or KN95 underneath with a multi-layer cloth mask on top.  For those who want maximal efficacy, using a mask brace is the most effective. I can see that wearing a mask brace may be cumbersome if you are just popping into the store. But if you need to go all day with a mask, it is worth the effort. And, it can be more comfortable. Otherwise, double-masking is the best option.

Effective mask wearing is simply a skill we all need to learn. It’s not difficult, and making the minimal effort necessary to be an effective mask-wearer is a sign of being a good citizen and showing basic consideration for each other. The flip side of this is that not wearing a mask properly when the situation calls for it shows flagrant disregard for the health of others. It’s like speeding through school zones, or violating health codes in a restaurant. Don’t make this political or tribal. The evidence is clear. We all need to be adults and do the right thing, even though it may be a small inconvenience.

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