When a new virus blasts out of the animals that harbored it and into people, experts can usually say, thank goodness it’s not like measles. That virus is more contagious than any others known to science: Each case of measles causes an astronomical 12 to 18 new cases, compared to about six for polio, smallpox, and rubella. Each case of the new coronavirus is estimated to cause two to three others.
The reason the measles is so, well, viral, is that the microbe is so small and hardy that it is able to stay suspended in the air where an infected person coughed or sneezed for up to two hours, making it one of the only viruses that can exist as a true aerosol.
Now there are conflicting reports on whether the new coronavirus can. The studies suggesting that it can be aerosolized are only preliminary, and other research contradicts it, finding no aerosolized coronavirus particles in the hospital rooms of Covid-19 patients.
The weight of the evidence suggests that the new coronavirus can exist as an aerosol — a physics term meaning a liquid or solid (the virus) suspended in a gas (like air) — only under very limited conditions, and that this transmission route is not driving the pandemic. But “limited” conditions does not mean “no” conditions, underlining the need for health care workers to have high levels of personal protection, especially when doing procedures such as intubation that have the greatest chance of creating coronavirus aerosols. “I think the answer will be, aerosolization occurs rarely but not never,” said microbiologist and physician Stanley Perlman of the University of Iowa. “You have to distinguish between what’s possible and what’s actually happening”