Skeptics of the notion that the coronavirus spreads through the air — including many expert advisers to the World Health Organization — have held out for one missing piece of evidence: that floating respiratory droplets called aerosols contain live virus and not just fragments of genetic material.

A team of virologists and aerosol scientists has produced exactly that: confirmation of the infectious virus in the air.

Linsey Marr, an expert in the airborne spread of viruses who was not involved in the work, said the findings are what people have been clamoring for.

“It’s unambiguous evidence that there is an infectious virus in aerosols.

A research team at the University of Florida succeeded in isolating live virus from aerosols collected at a distance of seven to 16 feet from patients hospitalized with COVID-19 — farther than the 6 feet recommended in social distancing guidelines.

The findings, posted online last week, have not yet been vetted by peer review but have already caused something of a stir among scientists.
“If this isn’t a smoking gun, then I don’t know what is,” Marr tweeted last week.

But some experts said it still was not clear that the amount of virus recovered was sufficient to cause infection.