Did Face Masks Help Fight COVID? Scientists Want You To Wear Yours Again

There is a new COVID-19 variant in our midst, and it seems to be spreading across the globe at a rapid rate. But is it time once again to "mask up?" And did masks actually work the first time round?

The new strain of COVID-19 is called EG.5, or "Eris." The World Health Organization (WHO) has declared it a variant of interest, meaning it is being closely monitored. Eris—which is a subvariant of the variant Omicron—is now the most common in the U.S, making up 17 percent of all cases. As of August 8, it has also been detected in more than 50 countries.

During 2020 and 2021, when the world was in the grips of the pandemic, masks were widely adopted as a way to prevent the spread. And in many public settings, they were mandatory.

The choice of whether to wear one is now optional, but as Eris continues its rapid spread, scientists are once again noting how effective they are in preventing high infection.

"Yes they do [work]. There are many lines of evidence that show they do, from clinical to population and laboratory studies," epidemiologist Raina MacIntyre, a professor of global biosecurity at the Kirby Institute at University of New South Wales, Australia, told Newsweek.

"But what we refer to as masks can vary from a cloth mask to a surgical mask to an N95 respirator. A cloth mask provides the least protection and an N95 the most. But even a cloth mask is better than nothing against SARS-CoV-2 as shown in a large U.S. study."

That 2022 study, from the Centers for Disease Control and Prevention, found that between February and December 2021, using a face mask or respirator in indoor public settings was associated with lower chances of becoming infected with COVID-19.

Cloth masks were associated with a 56 percent lower risk, while surgical masks were associated with a 66 percent lower risk. Respirators were the most effective, linked to an 83 percent lower risk.

A 2022 meta-analysis of 44 studies of healthcare and non-healthcare workers published in The Lancet, the peer-reviewed journal, also found that using a face mask was associated with lower chances of infection. Again, it concluded that N95 masks provided more protection than cloth masks.

However, some studies had previously been interpreted as casting doubt on the efficacy of masks. One from 2021, published in the peer-reviewed Southern Medical Journal, looked at the impact of mask mandates on mortality and intensive care admissions in Bexar County, Texas, from July 8 to August 12, 2020. It did not find that the mask mandates had any effect, but did not examine the efficacy of mask wearing itself.

A review of 78 studies from the Cochrane Library, the respected scientific nonprofit, in January 2023 also looked at the impact of mask mandates and interventions. Its results were interpreted by some as proof that masks don't work. However, Cochrane Editor-in-Chief Karla Soares-Weiser said in a statement in March that such an interpretation was flawed.

"Many commentators have claimed that a recently updated Cochrane Review shows that 'masks don't work,' which is an inaccurate and misleading interpretation," she wrote. "It would be accurate to say that the review examined whether interventions to promote mask wearing help to slow the spread of respiratory viruses, and that the results were inconclusive."

MacIntyre, who is also a National Health and Medical Research Council principal research fellow, leads a research program on the prevention and control of infectious diseases. She does not doubt the importance of wearing masks in healthcare settings.

"SARS-CoV-2 has not gone away, has not mutated into a cold, and still kills people. Many hospitals around the world are now reinstating universal masking after abandoning it a while ago, because they cannot function with high levels of staff illness and absenteeism; and patients are actually catching COVID in hospitals and dying from it," MacIntyre said.

"Masking is such an important and simple measure to protect staff and patients. Aged care is another setting. In the community, masks could be encouraged during periods of high community transmission in crowded public spaces."

MacIntyre is not the only scientist who advises people to wear masks during high periods of transmission. And since this new variant has emerged, some are expressing it more urgently.

Trisha Greenhalgh, a professor of primary health care at Oxford University in the U.K., said in a tweet that it is time to "mask up" once again as the new variant continues to spread.

"My various science WhatsApp groups are buzzing. Genetic lineage clips and diagrams flying back and forth. I understand little of the detail but it looks like it's once again time to MASK UP, " she said.

My various science WhatsApp groups are buzzing. Genetic lineage clips and diagrams flying back and forth. I understand little of the detail but it looks like it's once again time to MASK UP.

Professor Christina Pagel, a mathematician from the Clinical Operational Research Unit in University College London, U.K.—specializing in operational research, data analysis and mathematical modeling relating to topics in healthcare—has also widely spoken about how masks prevent the spread, and is now warning against the effects of Eris.

"To everyone else - v v early days but this coronavirus variant (now in 2 countries) has a LOT of new mutations that makes it v different to previous Omicron strains - and so potentially more able to cause a big wave," Pagel said in a tweet.

Flagging to @PeacockFlu & @CorneliusRoemer & @TWenseleers To everyone else - v v early days but this coronavirus variant (now in 2 countries) has a LOT of new mutations that makes it v different to previous Omicron strains - and so potentially more able to cause a big wave. https://t.co/3kxcIRwrf4

All viruses change and mutate—Eris is not the first variant of COVID-19 we have seen.

So this development is not too alarming, and certainly not a surprise to scientists.

From what scientists have seen so far, Eris is not more severe than other variants. But it is still COVID-19—which, as of August 16, has caused nearly 7 million deaths worldwide, according to WHO.

"The new variant is concerning because the latest booster vaccinations will not provide good protection. It is not more severe than other variants seen this year, but similar, which is bad enough," MacIntyre said.

Eris is more closely related to the XBB variants, or Omicron, which was first detected by WHO in 2021, MacIntyre said. But the XBB booster vaccination is not yet available.

"In May, WHO recommended boosters targeting XBB. Unfortunately, with the end of the emergency declaration, this has implications for the speed of availability and the cost of new boosters," MacIntyre said. "The U.S. may get these in October, but masks are more important when a highly immune evasive variant emerges—that is, a variant that is not well matched to existing vaccines. COVID remains a leading cause of death worldwide, and has caused a drop in life expectancy in the U.S."

COVID-19 is mostly a danger to vulnerable people—someone who either has an existing condition, or the elderly, for example. This means those who are younger and healthy may not be as badly affected, and may even have no symptoms.

"The reason masks are important is that about 30-50 percent of infections are asymptomatic—so you would not know if you yourself were infected or if others around you are. That is why masks make a difference," MacIntyre said.

"They work both by reducing the risk of well people getting infected, and the risk of infected people spreading it. SARS-CoV-2 is predominantly spread through aerosols, and by inhalation—not, as popularly believed, by someone sneezing in your face. That may cause infection too, but is less common, as an airborne virus can remain viable in the air for hours, and can infect people who simply breathe in that air."

While masks do not eliminate the spread completely, they still protect against a high viral load being spread.

"There has been a huge amount of research on this during COVID, which shows that ventilation (even opening a window) and masks reduce that risk.

"Sometimes even when wearing an N95 [respirator], people can get infected, but the dose of exposure to the virus will be lower, and the person may not get as sick—this is the dose-response relationship which is well established in virology," MacIntyre said. "The higher the initial exposure, the sicker you will get."

Updated, 08/17/2023, 1 p.m. ET: This article was updated with additional information.