Get Shot, Show Face? How Mask Rules Are Changing

(Bloomberg) --

More than a year after masks began to blossom on the streets of many cities in response to the Covid-19 crisis, guidance over how best to use them continues to change. In January some European governments required medical-grade coverings in public settings in response to new variants of the coronavirus that causes Covid-19. One of U.S. President Joe Biden’s first acts in office was to break with his predecessor by issuing a nationwide, if limited, mask mandate. In April and then again in May, however, U.S. health authorities relaxed their recommendations for fully vaccinated people. Here’s a look at some of the issues involved.

1. How did the debate start?

As the Covid-19 pandemic unfolded, authorities in different places said different things about whether healthy people should wear face masks to reduce the spread of the disease. Starting mostly in Asia, officials recommended or mandated face coverings in crowded places such as stores, buses or subways. Experts at the World Health Organization and in the U.S. initially said there was no such need. The U.S. Centers for Disease Control and Prevention changed its position in April 2020, and the WHO did so two months later. By the end of last year, two-thirds of governments had made wearing masks in public places compulsory nationwide.

2. How can masks help?

The evidence so far is that the coronavirus causing Covid-19 spreads predominantly in respiratory droplets -- spatters of liquid expelled when an infected person coughs, sneezes or even speaks. Transmission can occur if the droplets reach the mouth, nose or eye of someone nearby, either directly or from an unwashed hand that’s touched a contaminated surface. When an infected person wears a face covering, the droplets can be caught by the mask rather than being expelled. Masks may also help block transmission via aerosols that theoretically occurs when the virus travels through even smaller droplets that waft through the air. This could be especially useful against Covid-19, because evidence suggests that a third to half of transmissions occur from people who have not yet developed symptoms and so may remain out and about. Some studies show that wearing a mask also helps protect people who are uninfected.

3. Why did the WHO change its guidance?

A review of 172 studies funded by the WHO and published June 1, 2020 concluded that mask-wearing protects the public against infection by the coronaviruses responsible for the Covid-19 pandemic, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). More backing has come out since then. (Previous studies had not generally been considered conclusive.) Before changing its tune, the WHO had cautioned that use of masks by healthy members of the public may create a false sense of security, leading people to neglect essential measures such as hand-washing and keeping at a distance from others. It also said wearing a mask can encourage people to touch their faces, which can increase the chances of becoming infected with the coronavirus.

4. What happened to those concerns?

They’re still around. Health-care professionals emphasize that it’s vital to wear a mask correctly or you could become infected through contact with it: Put it on with clean hands, replace it when it becomes damp, remove it from behind without touching the front, wash your hands afterward, and discard a disposable mask properly. The WHO counsels against reusing masks that are made for a single use.

5. How did Biden change the U.S. policy?

Biden mandated that masks be worn in airports as well as on commercial airplanes, trains, ferries, intercity buses and other forms of public transportation. He ordered their use in federal buildings, on federal lands and by federal employees and contractors. And he instructed national officials to encourage mask use across the country. His predecessor, Donald Trump, had downplayed the importance of masks and left it to state officials whether to require face coverings in public.

6. How did vaccinations change the U.S. situation?

As the country’s vaccine rollout progressed, the CDC in April said fully vaccinated people could be unmasked when exercising, dining and socializing outdoors in small groups, or when gathering indoors with other fully vaccinated people and family members. Then, in May, the agency said fully vaccinated people could resume most activities without masking, unless otherwise required by law, regulations or the guidance of businesses or workplaces. It said vaccinated people should continue to wear a mask on planes, buses, trains and other forms of public transportation and in transportation hubs such as airports and stations.

7. What’s changed elsewhere?

Germany and Austria have made medical-grade coverings mandatory in shops and on public transportation, while France requires either those or fabric masks that meet the specifications of medical ones. Those changes came in response to the spread of the new coronavirus variants that appear to be especially contagious. The European Centre for Disease Prevention and Control relaxed its mask-wearing guidelines for fully vaccinated people in April, saying they have low risk of contracting or spreading the virus, although it suggested that even vaccinated people continue to wear masks in public spaces or indoors with people from other households. Israel lifted an outdoor mask mandate after a massive vaccination effort. The WHO suggests medical masks for health workers, anyone with Covid symptoms or caring for someone with symptoms, those age 60 and older, and anyone with a pre-existing medical condition. It recommends that others use non-medical masks so as not to replicate the shortages of medical-grade versions among health-care workers that were seen early in the pandemic in many places and that persist in the U.S.

8. How are medical masks different?

While fabric masks come in innumerable styles, with some people hand-sewing them or improvising them using bandannas or scarves, medical masks are regulated devices that come in two types. Surgical masks are the loose-fitting, one-size-fits-all kind that are rectangular when flat. These are the type usually given to patients infected with the virus. Health-care providers who deal with such patients are directed to wear a more sophisticated mask called a respirator, which is designed to protect the user. They come in different sizes so they can be fit to the face to provide a tight seal. That forces the user to pull air through the device’s filter rather than through gaps on the sides. They are designed to keep out not only respiratory droplets but also smaller aerosolized particles that can carry infectious agents and float for a time through the air. Respirators are uncomfortable to wear for a long period of time. They retain heat and exert pressure on the face, and some people find they make it difficult to breathe, which can make them unsuitable for those with cardiac and respiratory conditions.

9. What’s the U.S. guidance on double-masking?

Following the release of a CDC study in February that found double-masking can boost protection from aerosolized particles, the agency began recommending that people wear either a cloth mask with multiple layers of fabric or a surgical mask beneath a cloth one. In the latter case, the goal is to have the second mask push the edges of the inner mask against the face to provide a snug fit. The CDC also recommended using masks that have a metal strip that bends over the nose to prevent air leakage. It advised against combining a respirator with another mask.

The Reference Shelf

• Related QuickTakes on virus mutations, vaccine dosing and long Covid.
• The CDC study on the value of improving mask fit, and relaxed guidance for vaccinated people.
• A review of the evidence on face masks and coronavirus transmission published in the Proceedings of the National Academies of Sciences.
• The WHO-funded review of studies on mask-wearing and coronavirus transmission.
• Guidance on masks from the World Health Organization.

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