From a letter in a reputable-looking publication, submitted Oct 2020 and published in December:

"The authors correctly cite measles and tuberculosis as airborne infections, but neither has ever been isolated as viable pathogens from air samples [20, 21], whereas SARS CoV2 has [6]. Airborne transmission has been subject to a much higher burden of proof than droplet or contact transmission of SARS-COV-2, and also to a higher evidence standard compared to other pathogens. This is the opposite of a precautionary approach in the face of uncertainty."

Ref: https://aricjournal.biomedcentral.com/articles/10.1186/s13756-020-00868-6#citeas