CDC updating guidance to say that COVID can spread via aersols

https://www.nytimes.com/2021/05/07/health/coronavirus-airborne-threat.html?action=click&module=Top%20Stories&pgtype=Homepage

Why it took so long to correct the guidance:

https://www.nytimes.com/2021/05/07/opinion/coronavirus-airborne-transmission.html?action=click&module=RelatedLinks&pgtype=Article