Wearing a face mask can reduce coronavirus transmission by up to 75%, study says

HONG KONG– Researchers have found that wearing surgical masks can significantly reduce the rate of airborne COVID-19 transmission, according to a study released on Sunday.

The study, conducted by a team of scientists in Hong Kong, found the rate of non-contact transmission through respiratory droplets or airborne particles dropped by as much as 75 percent when masks were used.

“The findings implied to the world and the public is that the effectiveness of mask-wearing against the coronavirus pandemic is huge,” said Dr. Yuen Kwok-yung, a leading microbiologist from Hong Kong University who helped discover the SARS virus back in 2003.

It was released by the department of microbiology at the University of Hong Kong and comes as world leaders, including the World Health Organization (WHO), have questioned the effectiveness of face coverings outside of medical settings.

The study, described as a first of its kind, placed hamsters in two cages, with one of the groups infected with COVID-19 and the other being healthy. They placed the animals in three different scenarios to analyze the effectiveness of the face coverings.

In one scenario the mask barriers were placed only on cages with the infected subjects, another saw the masks covering the healthy subjects, and the third saw with no mask barriers at all. For all of the scenarios, a fan was placed between the cages to allow for the transmission of respiratory droplets.

They found that when the mask was placed over the infected cage the infection rate dropped to just over 15 percent.

That infection rate went up to 33 percent when the mask barrier was only used to cover the healthy hamsters’ cage.

With no mask barriers at all, roughly two-thirds of the healthy hamsters were infected with the virus within a week, the study found.

Researchers added that the hamsters who were infected even with the mask barrier had less of the virus in their bodies when compared to those infected without the masks.

“In our hamster experiment, it shows very clearly that if infected hamsters or humans — especially asymptomatic or symptomatic ones — put on masks, they actually protect other people,” Yuen said in a press conference on Sunday, according to Sky News.

“That’s the strongest result we showed here. Transmission can be reduced by 50 percent when surgical masks are used, especially when masks are worn by infected individuals.”

He said up until we have a vaccine for the virus, what remains practical is either social distancing or wearing a mask.

Last month, a separate study published by a group of international experts, created a model that shows cases of the virus could be cut significantly if “(near) universal masking” is adopted.

“Universal masking at 80 [percent] adoption flattens the curve significantly more than maintaining a strict lockdown,” researchers wrote in the study, which has not yet been peer-reviewed, as of last week.

“Masking at only 50 [percent] adoption is not sufficient to prevent continued spread,” the researchers added. “Replacing the strict lockdown with social distancing on May 31 without masking results in unchecked spread.”