Masks are simple, mask science is not

Mandates justified as evidence grows

A surgical mask and an N95 mask hang on display for sale at a pharmacy. (Sean Gallup/Getty Images)

Last Thursday, Gov. Jared Polis issued a statewide mask mandate. The announcement came on the heels of an uptick in statewide COVID-19 cases and immediately prompted backlash by some Republican leaders.

Mask wearing, like so many things, has become unreasonably partisan despite prominent health organizations and scientists widely supporting mask mandates. In the midst of a global pandemic that has already killed over 140,000 Americans, here’s what we know — and don’t know — about masks.

Masks are old news. Health care workers have long worn personal protective equipment, including masks, to reduce transmission of influenza and other respiratory illnesses, including coronaviruses SARS and MERS. For COVID-19, many studies now show the effectiveness of surgical and N95 masks among health care workers, and we now have modeling showing tens of thousands of lives could be saved with widespread mask use. We also have observations of mask mandates in the U.S. showing success in slowing COVID-19, and we even know that men are more likely to dismiss COVID-19 as a conspiracy theory and are therefore less likely to even wear masks.

These are incredible strides in research for a short amount of time, and more than enough to warrant a national mask mandate. These studies even suggest that exceptions for eating and drinking in enclosed public spaces probably shouldn’t exist. But what do we still need to learn?

It turns out, quite a lot.

COVID-19 is a new disease, and research is limited in time and scope. To date, despite evidence of efficacy for masks at large, we still lack peer-reviewed, randomized, controlled trials on homemade cloth masks, specifically regarding their effectiveness in reducing the spread of COVID-19 among the general public. This means research will now focus on nuances, such as variants by population (e.g. health care workers versus general population), mask type (e.g. homemade versus medical masks), mask design (e.g. material type, required layers), disease strain, and whether or not homemade masks can operate in isolation as preventative measures to reduce transmission.

Limited evidence suggests cloth masks may not always be as effective as medical masks and that health care workers may be better at using masks than the general public. These aren’t surprising findings, and with added research it’s possible we could improve homemade mask designs and improve public education to boost community effectiveness. Regardless, a cloth mask is better than no mask, and learning more will help shape public policy and public health informational campaigns, ranging from who and how to best educate on mask wearing, the ability to provide optimized mask design templates, and to what extent, if any, we may need to alter physical distancing mandates. It is also of direct value in determining how to safely reopen schools, businesses and more.

Above all, we must continue to understand transmission of the novel coronavirus. There is currently mixed data on whether or not SARS-CoV-2 particles remain airborne. Cloth and surgical masks best reduce droplet transmissions, a mode of infection that has been well established for this virus. If, however, the virus is also airborne, this will reduce the effectiveness of cloth and surgical masks, prompting stronger physical distancing measures to remain in place longer. It may also accelerate the need for respirator storage and production, as these masks are nearly impossible to make at home. This continued uncertainty in mode of transmission is why frontline health care workers are encouraged to use respirators, face shields and other protective gear whenever available. (Due to shortages, do not use a respirator or N95 mask if you are not a health care worker.)

For now, a combination of preventative measures, including masks with physical distancing, seems to have the largest impact on reducing transmission of COVID-19. As masks are most effective when widely used, nationwide mandates are vital. It truly takes a village.

Responding to a global pandemic in real time is a significant scientific and political challenge. Decisions must be made swiftly with the best available information at the time. Today, mask mandates are rightfully driven by existing studies, even if much is still in development. Masks are easy additional preventative measures, and the potential benefits far outweigh any costs.

We are learning more every day. As new data is published, guidance for the public can, and should, change. Today, the governor is absolutely right to mandate masks, and the same should happen federally — not because the science is clear, but rather, at least in part, because it isn’t.