Â鶹ӰÊÓ

Skip to main content

Coronavirus variants 'better at travelling through the air,' raising transmission risk, study finds

Share
TORONTO -

A new study has found that SARS-CoV-2, the virus that causes COVID-19, is evolving to get better at becoming airborne in its newer variant forms, raising concerns that loose-fitting face masks only provide "modest control" against infection.

The study, led by the University of Maryland School of Public Health, reports that the virus has moved towards "more efficient aerosol generation." Researchers say this means that public health measures will be needed to protect those in public-facing jobs and working indoors until vaccination rates are "very high."

Those measures include improved ventilation, increased filtration, UV air sanitation and tighter-fitting masks, in addition to vaccines.

The study was published Tuesday in peer-reviewed .

Results of the new study show that people infected with the Alpha variant expelled 43 to 100 times more virus into the air when they breathed than people infected with the original strain of the virus.

The study notes that this was the dominant strain that was circulating during the research period.

Don Milton, professor of environmental health at the University of Maryland, said the findings provide further evidence that transmission of COVID-19 is primarily airborne, spreading from the nose and mouth of an infected person by sprays of large droplets when in close proximity.

"We know that the Delta variant circulating now is even more contagious than the Alpha variant. Our research indicates that the variants just keep getting better at travelling through the air, so we must provide better ventilation and wear tight-fitting masks, in addition to vaccination, to help stop spread of the virus," Milton said in a .

Researchers found that the amount of airborne virus coming from Alpha variant infections was 18 times more than that of the amount of virus found in nasal swabs and saliva.

"We already knew that virus in saliva and nasal swabs was increased in Alpha variant infections," one of the study's lead authors and doctoral student Jianyu Lai explained in the release. "But our study shows that the virus in exhaled aerosols is increasing even more."

Researchers said that these increases in airborne virus from Alpha variant infections occurred before the Delta variant arrived in the U.S., indicating that the virus is "evolving to be better at travelling through the air."

To test how well masks work at preventing airborne spread, researchers measured how much COVID-19 is breathed into the air by infected patients and compared it to the amount of virus that is exhaled when they wear a cloth or surgical mask.

The study found that face coverings "significantly reduced" the amount of virus that is exhaled into the air from those infected with COVID-19 by about 50 per cent, but noted that loose-fitting cloth and surgical masks are unable to completely prevent virus particles from getting into the air.

Researchers said the study shows that a "layered approach" to virus control measures is "critical" to protect those returning to public work spaces.

"The take-home messages from this paper are that the coronavirus can be in your exhaled breath, [it] is getting better at being in your exhaled breath, and using a mask reduces the chance of you breathing it on others," Jennifer German, study co-author and assistant clinical professor at the University of Maryland, said in the release.

CTVNews.ca Top Stories

The British Columbia election campaign is set to officially start today, with Lt.-Gov. Janet Austin issuing the writ for the Oct. 19 vote.

A northern Ontario man is facing a $12,000 fine after illegally shooting a moose near the Batchawan River.

Unusual flippered feet are making their way into the Saint Lawrence River this weekend. Led by underwater explorer and filmmaker Nathalie Lasselin, volunteer divers are combing the riverbed near Beauharnois in Montérégie to remove hundreds of tires that have been polluting the aquatic environment for decades.

A sea lion swam free after a rescue team disentangled it near Vancouver Island earlier this week.

Local Spotlight

Cole Haas is more than just an avid fan of the F.W. Johnson Wildcats football team. He's a fixture on the sidelines, a source of encouragement, and a beloved member of the team.

Getting a photograph of a rainbow? Common. Getting a photo of a lightning strike? Rare. Getting a photo of both at the same time? Extremely rare, but it happened to a Manitoba photographer this week.

An anonymous business owner paid off the mortgage for a New Brunswick not-for-profit.

They say a dog is a man’s best friend. In the case of Darren Cropper, from Bonfield, Ont., his three-year-old Siberian husky and golden retriever mix named Bear literally saved his life.

A growing group of brides and wedding photographers from across the province say they have been taken for tens of thousands of dollars by a Barrie, Ont. wedding photographer.

Paleontologists from the Royal B.C. Museum have uncovered "a trove of extraordinary fossils" high in the mountains of northern B.C., the museum announced Thursday.

The search for a missing ancient 28-year-old chocolate donkey ended with a tragic discovery Wednesday.

The Royal Canadian Mounted Police is celebrating an important milestone in the organization's history: 50 years since the first women joined the force.

It's been a whirlwind of joyful events for a northern Ontario couple who just welcomed a baby into their family and won the $70 million Lotto Max jackpot last month.

Stay Connected