Covid-19 is transmitted through the air (airborne).

Judged as of 8 May 2021, against the scientific evidence and public health guidance of the time. True if the evidence then (peer-reviewed studies, WHO/CDC guidance) shows SARS-CoV-2 is transmitted through the air via aerosols or respiratory particles inhaled at short and longer range, including airborne/aerosol transmission. Mostly true if airborne transmission is established as a real route but the evidence shows it is mainly at close range or in specific settings, so a blanket 'airborne' slightly overstates it. Mixed if airborne transmission was then a contested hypothesis with substantial but not decisive support. Mostly false if the evidence showed aerosol transmission to be only rare or occasional, with other routes dominant. False if the evidence showed that SARS-CoV-2 is not transmitted through the air.

Set before the research began.

1. E1 NERVTAG and EMG: Role of aerosol transmission in COVID-19 - 22 July 2020 UK Government (NERVTAG and EMG advisory groups) · 22 July 2020

   “This is most likely to happen at close range (within 2 metres) though there is a small amount of evidence that this could happen in an indoor environment more than 2 metres from an infected person.”

2. E2 NERVTAG and EMG: Role of aerosol transmission in COVID-19 - 22 July 2020 UK Government (NERVTAG and EMG advisory groups) · 22 July 2020

   “There is no evidence of long-range airborne transmission (for example between different rooms in a building), such as occurs with measles and Tuberculosis (TB). SARS-CoV-2 is thought to be opportunistically airborne, with a risk of transmission through the air most likely to be within the same room and possibly the immediate neighbouring spaces.”

3. E3 Airborne transmission of SARS‐CoV‐2 via aerosols PubMed Central (rapid systematic review, peer-reviewed journal article) · 26 October 2020

   “Seven out of eight epidemiological studies suggest aerosol transmission may occur, with enclosed environments and poor ventilation noted as possible contextual factors.”

4. E4 Transmission of SARS‐CoV‐2 by inhalation of respiratory aerosol in the Skagit Valley Chorale superspreading event QUT ePrints (Indoor Air, 31(2), 314-323) · 4 March 2021

   “Transmission by the aerosol route is likely; it appears unlikely that either fomite or ballistic droplet transmission could explain a substantial fraction of the cases.”

A peer-reviewed systematic review found that seven of eight epidemiological studies suggested aerosol transmission may occur, especially in enclosed, poorly ventilated spaces (E3). A peer-reviewed analysis of the Skagit Valley Chorale outbreak concluded that aerosol transmission was likely (E4). These indicate that airborne transmission was a likely route before May 2021 [E3][E4], and UK advisory groups described SARS-CoV-2 as opportunistically airborne, mainly at close range or within the same room [E1][E2]. However, the UK advisory groups found that it was most likely at close range or within the same room, with only a small amount of evidence beyond 2 metres and no evidence of long-range spread between rooms (E1, E2). Under the criteria, that makes a blanket "airborne" a slight overstatement.