New COVID-19 variants are much better at airborne transmission that the initial novel coronavirus, according to a study in the Clinical Infectious Diseases journal.
For the study, University of Maryland researchers analyzed the Alpha variant, first identified in the United Kingdom. They discovered carriers with the variant breathed out 43 to 100 times more infectious viral aerosols than those infected with the original strain.
“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, in a press 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.”
People with variants such as Alpha and Delta carry a heavier viral load than those with the initial virus, so they exhale more particles, scientists explained. In the case of the Alpha variant, researchers found that the amount exhaled actually exceeded what was expected based on patients’ viral loads, which could indicate that the virus is getting better at airborne travel overall.
“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,” co-lead study author and doctoral student Jianyu Lai said.
Even with the increased viral output, face coverings – including loose-fitting cloth and surgical masks – can reduce the amount of exhaled viral particles by about half.
“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.
Researchers recommended tight-fitting masks, vaccination, improved ventilation in public spaces, air filtration and UV air sanitation as ways to cut down on virus circulation.