The first viral tweet of #COVIDisAirborne was a petition urging the WHO to promote broad awareness of aerosol transmission of COVID.

#COVIDisAirborne is a popular hashtag created on Twitter during the COVID-19 pandemic in response to the lack of awareness that COVID is spread predominantly through aerosols. 

The first use of the hashtag was on March 31, 2020 in a tweet by Twitter user @Kimberl06724725. The #COVIDisAirborne hashtag was used sporadically from that point onward but didn't pick up traction until Nov 2nd, 2020 when the "#COVIDisAirborne" petition was created on the Change.org platform urging the WHO to "urgently promote broad awareness of aerosol transmission." Prior to the petition, there was a Slate article written by Michael A. Fischer entitled "The Coronavirus Is Airborne. Keep Saying It," which may have inspired the phrasing.

The accompanying tweet was when the #COVIDisAirborne hashtag first went viral. Shortly thereafter, many scientists and engineers on Twitter such as Dr. Kimberly Prather, Dr. Jose-Luis Jimenez, Dr. Cath Noakes, Dr. Eric Feigl-Ding began using the #COVIDisAirborne in their tweets about the aerosol spread of COVID-19 (e.g. 1, 2, 3, 4). The hashtag then exploded in popularity. As of October 2021, there are hundreds of tweets using the #COVIDisAirborne hashtag per hour.