Masks save lives: Here’s what you need to know – Harvard Health Blog
Soaring rates of COVID-19 across the country and in many parts of the world make our efforts to protect ourselves and others more important than ever. Yes, the predictions are dire, but we are not helpless. Experts believe that we can save hundreds of thousands of lives and dramatically increase the chances of controlling the pandemic if we all commit to wearing a mask and following the usual preventative measures: maintaining physical distance; wash your hands frequently; avoid others if you are ill; and isolate yourself and get tested if you come into close contact with someone with the disease.
So why do we think masks work?
At the onset of the pandemic, experts expressed skepticism that the masks would be useful to the general public, especially in places where the virus has little or no spread in the community. Also, to avoid worsening the shortage of medical grade masks for health workers who needed this protection, masks were not widely recommended.
But we’ve seen a rapidly expanding body of evidence supporting the benefits of non-medical masks and fabric face coverings. Some of the strongest evidence includes these reviews (here and here) and observational studies (here, here, here, and here), which have found that wearing a mask leads to lower infection rates. And this impressive graphic display of the New York Times shows how masks help trap large respiratory droplets and some of the smaller particles called aerosols.
No study is perfect or definitive; in fact, such studies would be impossible to carry out. But there is a lot to wear when wearing a mask, and little or no evidence that wearing a mask causes harm. So, if you’re a person who wants to avoid COVID-19, cares about the health of others, and approves of rational, evidence-based decision making, choosing to wear a mask should be an easy call.
Where are we still looking for answers?
Here are some of the most common and important questions that we don’t have good answers for yet.
- What type of mask is the best? According to the CDC, it’s best to choose one with at least two layers of a “washable and breathable” fabric. A tightly woven fabric is a good choice. Gaiters and bandanas may offer little protection and are usually not the first choice, as they weren’t designed to provide tight facial coverage and usually only have one layer. Masks with vents or valves are also not recommended, as viral particles can more easily escape through them.
- Does wearing a mask protect others, the wearer, or both? At the start of the pandemic, when the evidence was more limited, wearing a mask was primarily recommended to protect others. Since then, we have learned a lot about the contagion of the virus and its spread. Currently, the evidence suggests that the person wearing a mask also derives some benefit from it. A recent Danish study questioned the protective effect of masks for the mask wearer. But within the community where the study took place, infection rates were not high and the general use of masks was rare; use of an appropriate mask was also self-reported. More generally, research clearly shows that the greatest overall benefit occurs when everyone wears a mask.
- Do masks reduce the severity of infection? Since masks can reduce the ‘dose’ of exposure to the virus and that lower exposure could result in less severe infection, some have suggested that wearing a universal mask could induce immunity with less fatal infections. . This remains controversial and unproven, however, and should not be taken as true. One concern is that if mask wearers believe they are protected from serious infection, they may relax social distancing or other mitigation measures while wearing a mask.
- Is it necessary to wear a mask outside? It depends on the situation. If you are going for a walk outside and no one is there, wearing a mask seems unnecessary. On the other hand, if you are walking near or with other people, or if you are at an outdoor gathering where it is not possible to keep a distance, wearing a mask is strongly encouraged. And of course, you need to follow local health regulations and mandates.
Mask do’s and don’ts
- A mask should fit snugly over the nose and mouth, with no space around the edges of the mask.
- The more comfortable a mask, the more likely you are to wear it. Try out a few styles and fabrics to see which one works best for you.
- Wash masks regularly.
- Anything other than a comfortable blanket over your nose and mouth may not offer much protection for you and those around you. Avoid “exposed nose”, “chin layer”, “hanging earring” and other creative approaches that prevent the mask from completely covering your nose and mouth.
The bottom line
If we are to make meaningful progress in ending – or at least slowing down – the pandemic, we must embrace science and expert opinion. We also need to recognize that there are areas of uncertainty and expect recommendations to change as we learn more. Changing guidelines do not mean that ‘the experts don’t know what they are doing’ (as I have heard more than once) – in fact, it is usually a sign that the experts are doing their best. job.
The best available evidence shows that we should all wear masks, as this will reduce the spread of infection and save lives. It is much more difficult to make a convincing case against wearing masks.
Follow me on twitter @RobShmerling.
For more information on COVID-19, see the Harvard Health Coronavirus Resource Center.
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