The thousands of tiny fluid droplets that we spray during normal conversation are a potentially significant way the new coronavirus spreads from person to person, according to a report on Wednesday in the Proceedings of the National Academy of Sciences of the USA.
Using laser light scattering, researchers studied the small droplets that linger in the air after exiting the mouth. Based on earlier research into levels of the virus in oral fluid, they estimate that one minute of loud speaking could generate more than 1,000 virus-containing droplets that would remain airborne for at least eight minutes.
“There is a substantial probability that normal speaking causes airborne virus transmission in confined environments,” Philip Anfinrud and Adriaan Bax of the National Institutes of Health in Bethesda, Maryland and their coauthors conclude.
Scientists have found twin antibodies that neutralize the new coronavirus, each by slightly different mechanisms. Finding a way to use both antibodies simultaneously might be a particularly good way to attack the virus, the researchers say.
According to their report on Wednesday in Science, the two antibodies were isolated from a patient who recovered from COVID-19. Both work by attaching to a spike on the virus that helps it break into human cells. Because the antibodies each bind to different places on the spike, a “cocktail” containing both may be more effective than a treatment using either one by itself.
The information could also help in development of a preventive vaccine, the laboratory experiments suggest. Furthermore, even if the virus mutates so that one of the antibodies no longer works, the other might still retain its neutralizing activity.