Widespread use of masks could help prevent many people from getting COVID-19 during the next two months, lowering the projected New York State death toll by a range of 17% to 45% depending how carefully and frequently they are used, new research shows.
A study of data from New York by Arizona State University researchers suggests that immediate “broad adoption,” by 80% of New Yorkers, in using "moderately" effective face masks could have a significant impact on the spread of disease, along with other social distancing methods. Even “very weak masks” that are 20% effective help in blocking the virus, it concluded.
“Face mask use should be as nearly universal (i.e., nationwide) as possible and implemented without delay, even if most masks are homemade and of relatively low quality,” concluded the ASU team. “This measure could contribute greatly to controlling the COVID-19 pandemic, with the benefit greatest in conjunction with other nonpharmaceutical interventions that reduce community transmission.”
In Newsday interviews, the lead author of the study, Dr. Steffen E. Eikenberry, and another co-author, Eric Kostelich, estimated that widespread use of masks starting from the early onset of the crisis in New York could have lowered the current death toll by as much as 25%. So far, more than 16,500 New Yorkers have died from COVID-19.
“The study suggests the potential benefit tends to be greatest early in an epidemic, because you want to reduce the scale of the transmission rate — the more you can do it early in time, the more benefit you have overall,” Eikenberry told Newsday. “Don’t wait until things are already bad and you’re hitting or near the apex, because then your benefits from masks are much lower.”
The researchers examined data from New York and Washington State, two hard-hit areas early in the crisis, to come up with various mathematical scenarios in their study, which was partly supported by the Simons Foundation, created by Long Island philanthropists Jim and Marilyn Simons. The study was published April 21 in the medical journal “Infectious Disease Modelling.”
Though the effectiveness of face coverings vary widely — from the N-95 respirator and surgical masks to homemade cloth coverings — the study found virtually all masks had some benefit in reducing the disease’s spread, not only with infected persons but when worn by healthy people for prevention as well. Moderately effective masks were described as those that are 50% effective.
“This may be important to emphasize, as some people who have self-isolated for prolonged periods may reasonably believe that the chance they are asymptomatically infected is very low and therefore do not need a mask if they venture into public, whereas our results indicate they (and the public at large) still stand to benefit,” the study concluded.
Masks have been much debated since the coronavirus outbreak began. For several weeks during the initial crisis, federal health officials urged people to wash their hands and keep their distance from infected people but said there was no pressing need for the public to wear masks unless they were sick.
In particular, high-quality masks, like the N95 respirators and surgical masks, were hard to obtain and were desperately needed by health care workers in places like New York, overwhelmed by thousands of patients sick with COVID-19. As a result, much of the public in New York City and Long Island carried on without masks, even after Gov. Andrew M. Cuomo’s stay-at-home directive on March 22.
But on April 3, the Centers for Disease Control and Prevention changed its advice on masks, recommending that people wear nonmedical coverings on their faces when in public, especially in places like grocery stores and pharmacies. CDC officials said new research showed that “asymptomatic” people — infected but without symptoms — could transmit the virus and that masks could help prevent it from spreading.
“This means that the virus can spread between people interacting in close proximity — for example, speaking, coughing, or sneezing — even if those people are not exhibiting symptoms,” the CDC said in announcing the change.
President Donald Trump said the new guideline was voluntary and declined to wear a mask himself. Today, medical masks are still difficult to find, so people increasingly wear their own homemade masks, cut from cloth and old garments. Those are the least effective of the masks, but still provide some protection; single-use face masks, such as those often handed out at doctor's offices, are considered "moderate."
The lack of mask-wearing by the public during the early days of the coronavirus crisis was one of several early misjudgments by U.S. officials, say critics like Columbia University Dr. Siddhartha Mukherjee, author of the Pulitzer Prize-winning book “The Emperor of All Maladies: A Biography of Cancer.”
“When the nation started this conversation — the worry was that there weren’t enough N95 respirators, and there was a worry people would hoard them,” Mukherjee recently told The New Yorker magazine. “And my fear is that to hide that misjudgment — that there weren’t enough, and they weren’t prepared — the government made a second misjudgment, which is that these masks are not protective. But that doesn’t make sense. If they are protective for doctors, why would they not be protective for the public?”
The Arizona State researchers acknowledge this national debate in their study, which is full of various mathematical scenarios outlining what impact mask-wearing can have in the future. It also notes the impact that wearing masks had in preventing illness with past pandemics, like the H1NI influenza outbreak, and figure that into their estimates.
The study examined New York State death data beginning March 1 through April 2 to come up with its future projections, concluding that “broad adoption of even weak masks use could help avoid many deaths.”
With more New Yorkers now wearing masks, Eikenberry said he hopes the study’s projected death toll at the end of two months will be on the lower side. He is the co-author of another recent study showing that the early worst-case scenario for New York, estimating 105,100 total deaths by the end of the pandemic, could be reduced by 80% if widespread mask-wearing and other social distancing methods are kept in place until the end of May or June.
But Eikenberry and his colleagues warned that masks and other precautions should also continue to avoid a resurgence of the virus this fall, with a “second wave” expected by many experts. “Early termination of the strict social-distancing measures could trigger a devastating second wave,” they said, “with burden similar to those projected before the onset of the strict social-distance measures were implemented.”
Mask types and effectiveness
Respirator: The most effective type of mask, known as an N95. Generally reserved for frontline medical workers, not the general public.
Surgical mask: A loose-fitting, disposable device creating a physical barrier between the mouth and nose of the wearer and potential contaminants in the immediate environment. User should make sure there are no gaps between face and mask.
Homemade cloth masks: The Center for Disease Control and Prevention recommends people use simple cloth face coverings when in public. It allows people who may have the virus to avoid transmission to others. Effectiveness varies, but generally less than the N95 respirator mask or surgical mask.
Sources: Food and Drug Administration, Centers for Disease Control and Prevention, World Health Organization