The Corner

Health Care

Does Mask Efficacy Justify Universal Mandates?

A man wearing a protective face mask walks past an illustration of a virus, in Oldham, England, August 3, 2020. (Phil Noble/Reuters)

I have never thought that opposing mask mandates was a hill to die on, as the interference on personal liberty is relatively minimal. But I don’t think that universal mandates are justified empirically or worth the adverse political ramifications they cause.

Mandates should require scientific certainty of efficacy, clear demonstration of need, and an unequivocal showing that no less-intrusive practicable means exists to accomplish the public-health goal. Orders requiring constant masking have not met this burden.

An interesting article by two public-health experts published on Real Clear Science backs my thinking. The authors found that masking appears to only have a modest impact on inhibiting COVID communicability. From, “Face Masks Don’t Work as Well in the Community as They do in the Lab”:

In controlled laboratory situations, face masks appear to do a good job of reducing the spread of coronavirus (at least in hamsters) and other respiratory viruses. However, evidence shows mask-wearing policies seem to have had much less impact on the community spread of COVID-19.

Why might this be?

There are several possibilities. Standard masks only protect your nose and mouth incompletely, for one thing. For another, masks don’t protect your eyes.

The importance of eye protection is illustrated by a study of community health workers in India. Despite protection by three-layer surgical masks, alcohol hand rub, gloves, and shoe covers, 12 of 60 workers developed COVID-19. The workers were then supplied with face shields (which provide eye protection) — in addition to the personal protective equipment (PPE) described above — and none of the 50 workers became infected despite higher case load.

So, are we also going to be forced to wear goggles? I don’t think so.

But aren’t masks supposed to protect others from the wearer, and not the other way around? Yes, but the evidence that they do is modest:

Why masks might fail to clearly protect others is more complex. Good masks reduce the spread of droplets and aerosols, and so should protect others.

In our systematic review we found three trials that assessed how well mask wearing protects others, but none of them found an obvious effect. The two trials in households where a person with influenza wore a mask to protect others in fact found a slight increase in flu infections; and the third trial, in college dormitories, found a non-significant 10% relative reduction.

The authors suggest a more-targeted focus for mask wearing, rather than one requiring that we don coverings whenever in public:

Until we have the needed research, we should be wary about relying on masks as the mainstay for preventing community transmission. And if we want people to wear masks regularly, we might do better to target higher-risk circumstances for shorter periods. These are generally places described by “the three Cs”: crowded places, close-contact settings, and confined and enclosed spaces. These would include some workplaces and on public transport.

We are likely to be better off if we get high usage of fresh masks in the most risky settings, rather than moderate usage everywhere.

This makes eminent sense. Many people bristle at being told to do something all the time — suspecting (perhaps paranoidly) that the orders are about exerting social control rather than actually preventing disease. In this sense, issuing broad-based mandates not demonstrated by “the science” can be counterproductive.

Educating us about the times in which masks can really help — as opposed to issuing diktats — would seem to be the wiser course, particularly in an individualistic country such as the United States.