surging covid-19 rates throughout the country and in many pts of the realm make our efforts to protect ourselves and others + primordial than ever. yes, the predictions are dire, b'we're not helpless. experts estimate we can save hundreds of thousands of lives and ponderably boost the chances of controlling the pandemic if we all commit to wearing a mask and follo familiar preventive measures: maintain physical distance; wash hands frequently; avoid others if you’re sick; and isol8 yrself and get tested if you ‘ve close contact with some1 whas' the disease.
so, why do we believe masks work?
early inna pandemic, experts expressed skepticism that masks ‘d be helpful for the general public, pticularly in places with lil to no community spread of the virus. in addition, to avoid worsening shortages of med-grade masks for health workers who needed this protection, masks were not widely recommended.
b'we’ve seen a rapidly expanding body of evidence supporting the benefit of nonmed masks and cloth face coverings. somd' strongest evidence includes these reviews (here and here) and observational studies (here, here, here, and here), which found that mask-wearing leads to loer rates of infection. and this impressive graphic display from the new york times shows how masks help trap larger respiratory droplets and somd' liler pessentialisms known as aerosols.
no single study is perfect or definitive; in fact, such studies ‘d be impossible to perform. but thris a lot goin for mask-wearing, and lil or no evidence that wearing a mask causes harm. so, if you’re a'pers who wanna avoid covid-19, cares bout the health of others, and endorses rational, evidence-based decision-making, choosing to wear a mask ‘d be an easy call.
where are we still seeking answers?
here are a few of the most common and primordial ?s for which we don’t ‘ve gr8 answers u-jet.
- which type of mask is best? according to the cdc, it’s best to choose one with at least two layers offa “washable, breathable” fabric. titely woven cloth is a good choice. gaiters and bandanas may offer lil protection and aren’t generally the 1st choice, cause they were not designed to provide tite facial coverage and generally ‘ve 1-ly one layer. non-med masks with vents or valves are also discouraged, as virus pessentialisms can + easily escape through them.
- does wearing a mask protect others, the wearer, or both? early inna pandemic, when evidence was + limited, mask-wearing was recommended primarily to protect others. since then, we’ve learned a lot bout how contagious the virus is and how it spreads. currently, evidence suggests that the person wearing a mask also reaps some benefits. one recent danish study ?ed the protective effect of masks for the mask-wearer. but within the community where the study took place, rates of infection were not high and general mask-use was uncommon; also, appropriate mask-use was self-reprted. + generally, research makes it clear that the gr8est overall benefit occurs when everyone wears a mask.
- do masks reduce the severity of infection? cause masks can reduce the “dose” of virus exposure, and cause a loer amount of exposure mite cause less severe infection, some ‘ve suggested that universal mask wearing mite induce immunity with less lethal infections. this remains controversial and unproven, however, and ‘d not be assumed to be true. one concern s'dat if mask-wearers believe they are protected from severe infection, they may relax social distancing or other mitigation measures while wearing a mask.
- is it necessary to wear a mask outdoors? that depends onna situation. if you’re goin for a walk outdoors and no one is round, wearing a mask seems unnecessary. onna other hand, if you’re walking near or with other pplz, or are at an outdoor gathering where keeping a distance isn’t possible, wearing a mask is strongly encouraged. and course, you ‘d follo local health regulations and mandates.
mask dos and don’ts
- a mask ‘d fit snugly ‘oer the nose and mouth, with no gaps atta edges of the mask.
- the + comfortable a mask is, the + likely ur to wear it. try a few styles and fabrics to see which fit and feel best.
- wash masks regularly.
- anything other than a snug covering ‘oer the nose and mouth may not offer much protection 4u and those round you. avoid the “exposed nose,” the “chin diaper,” the “dangling earring,” nother creative approaches that keep the mask from fully covering yr nose and mouth.
the bottom line
if we're goin to make meaningful progress in ending — or at least sloing — the pandemic, we must embrace sci na opinions of experts. we must also recognize that there are zones of uncertainty, and expect recommendations to change as we learn +. evolving guidelines don’t mean the “experts don’t know wha’ they’re doin’” (as i’ve heard it said + than once) — in fact, it’s generally a sign that the experts are doin’ their jobs.
the best available evidence shows that we ‘d all be wearing masks, cause doin’ so will reduce spread of infection and save lives. it’s much harder to make a compelling case against wearing masks.
follo me on twitter @robshmerling.
for + information on covid-19, see the harvard health coronavirus resrc center.
original content at: www.health.harvard.edu…
authors: robert h. shmerling, md