What kind of mask works best against the Delta variant?
Study shows surgical masks are more effective than cloth but are N95 and FFP2 the ones to have?
The debate about face masks has taken many twists and turns during the Covid pandemic.
Since July, masks have been optional in most public spaces in England, but the spread of the Delta variant of Covid-19 has led some to seek out more effective face coverings even as others abandon theirs.
Many health bodies and experts are advising people to get more serious. “Given the Delta variant that’s out there, you probably need to upgrade your mask,” Dr Ashish Jha, dean of Brown University School of Public Health, told Fox News earlier this month.
Initially, the public was advised against purchasing surgical-grade masks used by health professionals because of shortages of such protective gear. However, they are now more widely available and offer greater protection than standard cloth coverings.
Dr Peter Chin-Hong, an expert in infectious diseases at the University of California-San Francisco, told Quartz that now “a baseline should be a surgical mask”. He added that “even in the hospital, I’m mainly wearing a surgical mask”.
More effective still are N95 and FFP2 masks, said Wired. These are believed to protect both the wearer and those around them. The World Health Organization has cited studies showing the filtration systems of FFP2 and N95 masks are 94% and 95% effective respectively. However, they tend to be non-resuable so using them is expensive.
Raina MacIntyre, head of the biosecurity research programme at the University of New South Wales in Australia, who has conducted many studies on masks, said: “So definitely, masks need to be stepped up to fight Delta, but it does not mean those who cannot afford N95s have no options.”
She said a “high-performing cloth mask” can be fashioned to effectively block droplets, using a combination of cotton/linen and polyester/nylon – to resemble the performance of surgical protection.
The Centers for Disease Control and Prevention, the US public health agency, recommends that we can improve the fit of either a cloth or surgical mask by knotting the straps and tucking the sides. The rule of thumb is that a mask is generally a good fit if you feel warm air coming through the front of the mask as you inhale and exhale.
The Atlantic reported that researchers from several leading universities monitored roughly 350,000 adults in rural Bangladesh. As Quartz noted, the study found that villages where cloth masks were given out reported an 8.5% reduction in symptoms, while villages that received surgical masks reported a 13.6% reduction.
When a third of adults with symptoms commonly associated with Covid had blood tests, researchers discovered an 11% reduction among those who wore surgical masks but just a 5% reduction in infections among those who wore cloth masks.
“When I saw those results, I threw away my cloth mask,” said Stephen Luby, a co-author of the study. “If Delta is circulating and if you’re going to wear a mask, why don’t you wear one that the data tell you is good?”