New York and Los Angeles meet CDC criteria for wearing masks in public. How much will masks help this winter?
With the spread of covid at high levels in New York and Los Angeles, the Centers for Disease Control and Prevention now recommends that people in those areas wear masks indoors and on public transportation.
The CDC recommendation is based on three metrics: new Covid cases, hospital capacity, and hospital admissions. Both New York City and Los Angeles County recorded about 3,200 daily cases Thursday, and hospital beds in their respective states are more than 80% full, according to data from the Department of Health and Human Services.
Some cities are also asking for masks in schools in anticipation of the surge in cases this winter.
Philadelphia school district announced on wednesday that students and staff will be required to wear masks indoors for two weeks in January in an effort to reduce post-holiday transmission. The New York City Department of Education issued a letter this week strongly encouraging students and staff to wear a well-fitting mask indoors. And in Boston, parent advocacy group BPS Families for Covid Safety is urging the city school district to impose a 10-day mask mandate.
The number of people buying masks in the US has also increased over the past month, said Neil Saunders, managing director of retail at GlobalData, a research and consulting group.
“Much of this was initially related to increased travel and gatherings around Thanksgiving. However, part of the current increase could be due to growing health concerns around covid and flu,” Saunders said in an email.
However, after three years of Covid, experts recognized that few people are inclined to wear masks as often as before in public spaces.
“The reality is that most people find masks uncomfortable, so they’re going to choose” when to wear them, said Dr. Stephen Luby, a professor of medicine at Stanford University.
“Socially we’re in a place where people don’t feel like the hassle of wearing a mask is worth it in terms of the amount of protection they get, nor in terms of the amount of protection they provide to society at large.” he added she.
The masking effectiveness remains relatively unchanged from last December, when the original version of the omicron variant became dominant, said Linsey Marr, a Virginia Tech professor who studies aerosol transmission.
“The masks will work the same against omicron and really against any other version of SARS-CoV-2 that we are going to see because the virus is still the same size,” he said.
But as people tire of masks, studies examining their effectiveness have stalled, said Laura Kwong, an assistant professor of environmental health sciences at the University of California, Berkeley, School of Public Health.
“We have no clear studies evaluating the efficacy of the mask for alpha versus delta versus omicron, and definitely not within the omicron subvariants,” he said.
Marr said KN95 or N95 masks remain the most protective option, blocking 95% of airborne viral particles. A CDC study of mask wearers in California last year found that KN95 or N95 masks reduced the odds that a person would test positive for covid by 83%, compared to 66% for surgical masks and 56% for face masks cloth (although the results for cloth masks were not statistically significant).
“Any mask is going to be more protective than no mask at all, but at this point, if you’re going to bother wearing a mask, you might as well wear a KN95 or an N95,” Marr said.
Disease experts recommended masks even for people who are up to date on their Covid vaccinations.
By preventing infections, masks can reduce a person’s risk of long-term COVID, regardless of their vaccination status, Luby said.
Kwong noted that the masks also prevent people from transmitting covid to the elderly or immunocompromised. Kwong and Luby’s investigate in Bangladesh has shown that when 42% of the population wear masks, it can reduce Covid symptoms in people aged 60 and over by 35%.
Kwong said one trick in deciding when to wear a mask is to consider how close you are to the people around you: “Any place where people are breathing, talking, singing and you can reach out and touch someone, that’s a crowded space.”
Marr said it’s reasonable to weigh the benefits of socializing against the risk of getting sick.
“If it’s a holiday party, you get a lot of benefits from socializing with people you know,” she said. “There is less to gain by unmasking in the subway.”
But Luby said he still wears a mask in public, even when others around him don’t.
“I find myself in that situation a lot: I’m the only person in the room wearing a mask,” he said. “But on the other hand, I know that I am protecting myself and I know that I am protecting my family. when I’m doing that, so I’m willing to put up with a little bit of social approval.”