The Day – Mask mandates were a good idea but did they work?


States across the United States dropped their mask mandates this week, worrying Americans who think they’re still needed and encouraging people who are ready to “get back to normal.” Both groups need to take a deep breath: abandoning mask mandates is not the same as ignoring Covid-19.

Masks have been the most visible part of America’s response to the pandemic, but one of the least important. The fact that 500,000 people died during the omicron push means it’s time to change tack and focus on what went wrong that led to so many hospitalizations and deaths.

Mask mandates are based on the effectiveness of “universal masking” in which everyone wears a mask to reduce the number of cases. One of the leaders in proposing universal masking, UCSF’s Monica Gandhi, has been unfairly accused of being an anti-masker for speaking out about the limits of her own strategy and the far greater importance of vaccination campaigns. .

But there’s no avoiding it: the benefits of universal masking have been hard to quantify. A controlled study in Bangladesh showed a small but statistically significant benefit – among people who regularly used masks, 7.6% had symptomatic infections compared to 8.6% in the control group. Other studies have been inconclusive.

It is intuitive that a barrier should prevent germs from being emitted into the air. But if that’s true, why isn’t there more evidence of the benefits of masking two years into the pandemic? Experts associated with the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota presented a more complex analysis: Given the current understanding that the virus is transmitted by fine aerosol particles, it is likely that an infectious dose could easily pass through and around loose fabrics or surgical masks.

Many experts say only N95 respirators or similar devices are really effective at stopping this virus – and some, like CIDRAP chief Michael Osterholm, have gone public urging people to trust cloth masks less and adopt protective masks. respirators such as N95s. However, it does not advocate universal use of the N95 in schools, where children are unlikely to be able to wear them consistently or correctly.

Most people who only wore masks because of the mandate wore the least effective masks. Those worried enough to get an N95 aren’t going to stop because it’s not necessary. Future policies should aim to help people understand their risks and ensure that everyone who wants a supply of N95 masks can get one.

The most visible change will be in stores, and these are not the most dangerous places. Much riskier are crowded bars or private gatherings where people were already taking off their masks to eat and shouting to be heard. Several studies have shown that the louder someone speaks, the more particles they expel. Other studies show that prolonged exposure to others indoors is much riskier than transient exposures.

All of these factors may explain why states with mask mandates fared no better than the 35 states that did not mandate them during the omicron wave. Rhode Island, where I live, has had a mask mandate since mid-December; nevertheless, we saw our January push increase far more than any other state. There’s little evidence that mask mandates are the main reason pandemic waves end up falling — though much of the outrage over the lifting of mandates is based on that assumption. Many experts agree that the rise and fall of waves is a bit of a mystery, as epidemiologist Sam Scarpino explained to me on my podcast.

What is clear is that states with high vaccination rates have fewer hospitalizations and deaths, and that boosters are essential for anyone over 65 or at high risk of serious illness.

Megan Ranney, an emergency physician and dean of the Brown University School of Public Health, said most of her hospitalized patients were unvaccinated or lived in multigenerational homes and contracted the disease from younger members of the family. family who had skipped the injections. She sees no problem with the idea of ​​lifting mask mandates when the stress on hospitals has eased.

“Relaxing mask mandates is absolutely appropriate as cases drop below a threshold, particularly in high vaccination areas and particularly once hospitals are not in crisis mode,” she says. . She would have liked to see some states wait a bit longer, however, and says lifting school mandates should depend on both declining case numbers and vaccination rates among students exceeding 85%. (Vaccination rates are currently 23% for children 5-11 years old and 57% for children 12-17 years old.)

In other countries, mask mandates have been imposed and lifted with little or no rancor. Last week, I spoke to Michael Bang Petersen, a political scientist and psychologist who leads a pandemic behavior research project at Aarhus University in Denmark. There, remarkably, all restrictions were lifted this month with little controversy.

This is partly due to good communication and trust. “We can see that a clear majority of people feel they are getting clear information from the authorities,” he said.

And the Danish authorities have a realistic goal – not to minimize all cases or eliminate the virus, but to prevent the health system from collapsing. “I think if we look at how the Danish public thinks about coronavirus, they don’t see it as an individual threat… they see it as a societal threat,” he said.

Americans aren’t selfish — we’re also thinking about protecting society — but we’re deeply divided on what our obligations should be. One way to ease our tensions is to put the role of mask mandates into perspective.


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