SARS-CoV-2 Evolves To Get Better In The Air, New Study Finds

Results of a new study from the University of Maryland School of Public Health show that people infected with the virus that causes COVID-19 exhale the infectious virus in their breath – and those infected with the Alpha variant (the dominant strain circulating at the time the study was conducted) put 43 to 100 times more virus into the air than people infected with the original strains of the virus. The researchers also found that loose clothing and surgical masks roughly halved the amount of virus entering the air around infected people. The study was published in Clinical infectious diseases.

“Our latest study provides further evidence for the importance of airborne transmission,” said Dr. Don Milton, professor of environmental health at the University of Maryland School of Public Health (UMD SPH). “We know that the Delta variant that is currently circulating is even more contagious than the Alpha variant. Our research indicates that the variants keep getting better for air travel, so we need to provide better ventilation and wear masks well. adjusted, in addition to vaccination, to help stop the spread of the virus. “

The amount of virus in the air from Alpha-variant infections was much greater – 18 times more – than could be explained by the increased amounts of virus in nasal swabs and saliva. One of the lead authors, PhD student Jianyu Lai, explained, “We already knew that the virus in saliva and nasal swabs increases in Alpha variant infections. The virus in the nose and mouth can be transmitted by large droplet sprays near an infected person. But, our study shows that the virus in expired aerosols increases even more. ” These major increases in the airborne virus of Alpha infections occurred before the arrival of the Delta variant and indicate that the virus is evolving to move better in the air.

To test whether face masks block transmission of the virus between people, this study measured the amount of SARS-CoV-2 inhaled in the air and tested how much of the virus people with COVID-19 exhaled less. in the air after being strung. a surgical cloth or mask. The face coverings significantly reduced the virus-charged particles in the air around the person with COVID-19, reducing the amount by about 50%. Unfortunately, the loose fabric and surgical masks did not prevent the infectious virus from entering the air.

Dr Jennifer German, co-author, said: “The take-home messages from this article are that the coronavirus can be in your exhaled breath, improves in your exhaled breath, and using a mask reduces the risk. of you breathe it on others. ” This means that a layered approach to control measures (including improved ventilation, increased filtration, UV air sanitation, and properly fitted masks, in addition to vaccination) is essential to protect people in the areas. public jobs and interior spaces.