COVID-19 is evolving, ‘getting better’ at becoming an airborne virus

COLLEGE PARK, Md. — Recent COVID-19 variants are much more adept at airborne transmission than the original version of the coronavirus, according to a new study. University of Maryland researchers analyzed the Alpha variant originating out of the United Kingdom and discovered that carriers breathe out 43 to 100 times more infectious viral aerosols than those infected with the original strain.

On a positive note, study authors say certain face coverings usually cut the amount of exhaled viral particles in half.

“Our latest study provides further evidence of the importance of airborne transmission,” says Dr. Don Milton, professor of environmental health at Maryland’s School of Public Health (UMD SPH), in a university release. “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 traveling 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.”

Bigger viral loads entering the air

Scientists explain that these new variants result in a much larger “viral load” for infected carriers, which refers to the amount of the virus found within the body. However, the new study finds the amount of coronavirus released into the air by Alpha-variant carriers was significantly more (18 times) than what viral loads alone should be capable of doing. This suggests that SARS-CoV-2 is quite literally improving at airborne travel and transmission as time goes on.

“We already knew that virus in saliva and nasal swabs was increased in Alpha variant infections. Virus from the nose and mouth might be transmitted by sprays of large droplets up close to an infected person. But, our study shows that the virus in exhaled aerosols is increasing even more,” explains co-lead study author and doctoral student Jianyu Lai.

Meanwhile, face mask tests showed that commonly used face coverings like loose-fitting cloth and surgical masks reduce the amount of virus-laden particles released into the air while breathing, cutting the amount by about 50 percent. However, the results certainly don’t suggest face masks alone can offer full protection.

“The take-home messages from this paper are that the coronavirus can be in your exhaled breath, is getting better at being in your exhaled breath, and using a mask reduces the chance of you breathing it on others,” concludes study co-author Dr. Jennifer German.

Study authors recommend a “layered approach” to COVID-19 prevention in public or indoor areas including vaccinations, tight-fitting masks, improved ventilation, increased filtration, and UV air sanitation.

The study appears in the journal Clinical Infectious Diseases.