This Popular Mask Is "Not Great Against the Delta Variant," Virus Expert Warns
When it comes to keeping yourself safe, you might want to upgrade your PPE.
We may have used face masks to protect ourselves from COVID-19 since the earliest days of the pandemic, but they've taken on a whole new level of importance thanks to the Delta variant. The now-dominant strain has reversed the progress that was made in lowering case numbers thanks to its highly contagious nature, leading to a revival of universal mask mandates in many areas. But according to Ashish Jha, MD, dean of Brown's School of Public Health, you may want to consider upgrading from a cloth mask if you're trying to protect yourself against the Delta variant as well as possible.
During a Sept. 5 appearance on Fox News Sunday, Jha said the popular face coverings weren't the best option when it comes to stopping the spread of the virus. "Cloth masks, unto themselves, [are] generally not effective. That's why I think surgical masks are better," he explained. "There are, of course, higher-quality masks. Cloth masks may be ten or 20 percent effective, [which is] not great against the Delta variant. "
When pressed by host Chris Wallace over whether or not masks overall weren't effective in protecting against COVID-19, Jha pushed back with a clarification: "I'm saying that given the Delta variant that's out there, you probably need to upgrade your mask, Chris."
Jha's recommendation comes as a growing body of evidence suggests poorly fitted cloth masks might not be best suited to stop the spread of the highly contagious variant. One such large study, which was posted online on Aug. 31 and is currently being peer-reviewed for publication in the journal Science, tracked more than 340,000 adults in 600 villages in rural Bangladesh to examine the effectiveness of masks against the spread of COVID-19.
Most importantly, the researchers found there was a 9.3 percent reduction in symptomatic COVID cases and an 11.9 percent reduction in the prevalence of COVID-like symptoms when 42 percent of people wore masks. But while the study's results helped to further cement the effectiveness of mask use overall, it also found that there were some discrepancies between different types of PPE, specifically when it came to cloth masks.
The researchers noted that while cloth masks offered a 37 percent filtration efficiency, they paled in comparison to the 95 percent provided by surgical masks made of three layers of 100 percent non-woven polypropylene that were used in the study. "While cloth masks clearly reduce symptoms, we cannot reject that they have zero or only a small impact on symptomatic COVID infections," the authors wrote in their findings, leading the researchers to recommend the use of surgical masks over cloth ones. "Surgical masks have higher filtration efficiency, are cheaper, are consistently worn, and are better supported by our evidence as tools to reduce COVID-19."
Other recent research has been able to shed light on certain shortcomings of cloth masks. A study published in the journal Physics of Fluids on July 21 found that N95 and KN95 masks could provide particle filtration efficiencies of 60 percent and 46 percent, respectively. But while surgical masks saw a steep drop off in their effectiveness by providing efficiency of 12.4 percent, basic cloth masks performed the worst by offering only 9.8 percent.
"There is no question it is beneficial to wear any face covering, both for protection in close proximity and at a distance in a room," Serhiy Yarusevych, PhD, a professor of mechanical and mechatronics engineering and the leader of the study, said in a statement. "However, there is a very serious difference in the effectiveness of different masks when it comes to controlling aerosols."
Jha is also not the first health expert to advocate for higher quality face masks to protect against the Delta variant. During an interview with CNN in early August, Michael Osterholm, PhD, epidemiologist and director of the University of Minnesota Center for Infectious Disease Research and Policy, made the case that it was time for people to upgrade from DIY cloth masks to medical-grade products to keep themselves safe.
"We need to talk about better masking," he argued. "We need to talk about N95 respirators, which would do a lot for both people who are not yet vaccinated or are not previously infected. Protecting them as well as keeping others who might become infected having been vaccinated from breathing out the virus."