The federal government did a quick pivot on the threat of the coronavirus spreading through the air, changing a key piece of guidance over the weekend.
On Sept. 18, the Centers for Disease Control and Prevention warned that tiny airborne particles, not just the bigger water droplets from a sneeze or cough, could infect others. It cited growing "evidence."
By Sept. 21, that warning was gone from its website, with a note saying it had been posted in error and the CDC was in the process of updating its recommendations.
The move put the CDC in the middle of a debate over how the coronavirus infects people. Its guidelines could make the difference between restaurants, bars and other places where people gather fully reopening sooner or much later.
And it raised more questions about politics at the public health agency and whether White House officials are dictating policy to health authorities.
So what does the science on airborne transmission actually say?
The emerging picture is a work in progress, but many of the pieces do point toward the potential for airborne transmission.
THE CHALLENGE OF PROVING AIRBORNE TRANSMISSION
The CDC's retracted language said, "There is growing evidence that droplets and airborne particles can remain suspended in the air and be breathed in by others, and travel distances beyond 6 feet (for example, during choir practice, in restaurants, or in fitness classes)."
Why is this a big deal? It means the guidelines for proper physical distancing might need to be increased.